Automatic Drug Delivery Device

ABSTRACT

The invention relates to an automatic drug delivery device ( 10 ), in particular automatic drug delivery device, for dispensing a fluid product, in particular a fluid medicament, including: a longitudinal housing ( 104 ) extending along a longitudinal axis and having a proximal end close to the dispensing site, a distal end opposite to the proximal end and a hollow interior; a removable cap ( 50 ) mountable to the proximal end of the housing ( 104 ); a syringe assembly ( 200 ) arranged a mounting position inside the housing ( 104 ) and having a hollow syringe body ( 204 ) and an injection needle ( 206 ) coupled to the hollow syringe body ( 204 ) including the fluid product; a drive mechanism ( 300 ) which can be triggered by a trigger element in order to initiate the dispensing of the fluid product; wherein the loaded drive mechanism is operatively coupled with a safety shield ( 102 ) movable within the longitudinal housing ( 104 ), wherein the safety shield ( 102 ) is biased into a proximal position in which it protrudes out of the proximal end of the longitudinal housing ( 104 ) in order to cover a needle tip ( 348 ) of the injection needle ( 206 ), and wherein the safety shield ( 104 ) is movable into a distal position which the injection needle ( 206 ) is exposed for injection; wherein the removable cap is axially retained on the proximal end of the longitudinal housing by engagement of retaining elements between the cap and the longitudinal housing, the retaining elements being disengaged by rotation of the cap relative to the longitudinal housing to allow axial movement of the cap relative to the housing to remove said cap, the axial movement of the cap relative to the housing being supported by the biasing force applied to the safety shield.

FIELD AND BACKGROUND TO THE INVENTION

The present invention relates to an automatic drug delivery device, inparticular an autoinjector, for dispensing a fluid product, inparticular a fluid medicament to a patient.

Automatic drug delivery devices formed as autoinjectors are well knownin the prior art. There are different types of automatic drug deliverydevices available in the market. While current state-of-the-artautomatic drug delivery devices provide reliable functioning, they stillhave a number of drawbacks which are to be overcome.

European patent EP 2 745 866 B1 describes an automatic drug deliverydevice having a safety shield which acts as a trigger element. Theautomatic drug delivery device is triggered by pressing the safetyshield against an injection site on the patient's skin, where theinjection is to be performed. The safety shield is pushed into alongitudinal housing of the automatic drug delivery device and therebytriggers the injection process. When the injection is completed and whenthe automatic drug delivery device is removed from the injection site,the safety shield is pushed out of the longitudinal housing and blockedby a blocking mechanism in a safety position covering the needle tip.The blocking mechanism is formed within the safety shield and includesflexible arms in plural components. By this structure, the safety shieldbecomes complicated in geometry and manufacturing. Moreover, theflexible arms of this particular safety shield do not provide sufficientprotection against movement of the safety shield into the longitudinalhousing after use.

European patent EP 2 903 670 B1 describes an automatic drug deliverydevice which is activated by rotating an interlock member relative to anactivation member. Thereby, rotational relative movements betweendifferent components of the actuation mechanism are necessary. Suchrotational movements for activating the automatic drug delivery deviceare often not intuitive which makes the use of such automatic drugdelivery devices uncomfortable for the users. A further automatic drugdelivery devices having rotational components is known from EP 2 583 711A1.

Moreover, there are automatic drug delivery devices where the injectionprocess is triggered by pushing a button formed on the distal end or onthe circumferential side surface of the device. Such devices include thepotential of misuse as the triggering mechanism can be activatedalthough the drug delivery device is not placed correctly on theinjection site.

European patent EP 2 978 471 B1 describes an automatic drug deliverydevice which is also triggered by being pushed with the safety shieldagainst the injection site. The actuation mechanism, however, iscomplicated in its structure and requires plural parts interactingduring relative movements with one another. As a result, themanufacturing and the assembly is complicated.

US 2016/0331905 A1 describes an automatic drug delivery device includingan activation mechanism with a ratchet assembly. Different flexible armsinteract with a rack having indentations. Due to the plurality ofcomponents and moving elements the device is sensible in regard tomisuse and erroneous activation. Moreover, the manufacturing andassembly is complicated.

Besides the assembly and functioning of the activation mechanism, afurther issue of automatic drug delivery devices is the positioning andholding of prefilled syringe assemblies. Such prefilled syringeassemblies usually include a glass body prefilled with the fluid productto be dispensed. The glass body is to be handled with uttermost careduring assembling in order to avoid that the glass body is damaged orotherwise affected. In order to avoid direct handling of the glass body,this prior art document proposes the use of a syringe holder.

Reference is also made to document WO 2016/193374 A1 describing aparticular syringe holder having flexible arms which flex out in apre-assembled state and which relax if an axial force acts on thesyringe carrier. An alternative syringe carrier is described in WO206/193355 A1. This syringe carrier provides a biasing force onto thesyringe in axial direction within the housing of the automatic drugdelivery device. Another syringe holder providing an axial force on thesyringe is known from document WO 2007/083115 A1. Moreover, document WO2015/015230 A2 describes a syringe holder with a guard element fortransmitting axial loads to the syringe support. A further syringecarrier according to the prior art is known from WO/089620 A1, whichprovides an annular member interconnected by means of two connectionarms with a C-shaped proximal receiving member.

A further issue of automatic drug delivery devices is providing feedbacksignals to the user. Such feedback signals can be audible, visible ortactile signals. Document WO 2016/193343 A1 describes an automatic drugdelivery device with an audible indicator including resilient arms,which are deflected radially outwards during use and thereafter relax,whereby an audible signal is generated.

Moreover, another aspect of automatic drug delivery devices is using aremovable cap, which while being removed from the housing of theautomatic drug delivery device removes a rigid needle shield from theneedle of the prefilled syringe assembly. Such removable caps are knownfrom WO 2012/103140 A1. This document describes a relatively complicatedstructure of a removable cap having plural cap engagement mechanisms.

SUMMARY OF THE INVENTION

Cap Features

The present invention relates to an automatic drug delivery device fordispensing a fluid product, in particular a fluid medicament, including:

-   -   a longitudinal housing extending along a longitudinal axis and        having a proximal end,    -   a distal end opposite to the proximal end and a hollow interior;    -   a removable cap mountable to the proximal end of the housing;    -   a syringe assembly arranged in a mounting position inside the        housing, the syringe assembly having a hollow body and an        injection needle coupled to the hollow syringe body, the syringe        body including the fluid product;    -   a drive mechanism which can be triggered by a trigger element in        order to initiate the dispensing of the fluid product;    -   wherein the loaded drive mechanism is operatively coupled with a        safety shield movable within the longitudinal housing,    -   wherein the safety shield is biased into a proximal position in        which it protrudes out of the proximal end of the longitudinal        housing in order to cover a needle tip of the injection needle,        and wherein the safety shield is movable into a distal position        in which the injection needle is exposed for injection;    -   wherein the removable cap is axially retained on the proximal        end of the longitudinal housing by engagement of retaining        elements between the cap and the longitudinal housing, the        retaining elements being disengaged by rotation of the cap        relative to the longitudinal housing to allow axial movement of        the cap relative to the housing to remove said cap, the axial        movement of the cap relative to the housing being supported by        the biasing force applied to the safety shield.

The removable cap is axially retained on the proximal end of thelongitudinal housing by engagement of retaining elements between the capand the longitudinal housing. The longitudinal housing may include oneretaining structure for engaging at least one engaging structureprovided on the removable cap. The engaging structure may engage withthe retaining structure to hold the removable cap on the longitudinalhousing. Such an arrangement may enhance the security of the fit betweenthe cap and longitudinal housing.

The design of the retaining elements, for example the retainingstructure or engaging structure, can be designed to set the cap removalmethod, or at least provide a preferred removal method. For example, capremoval by pull-off may be blocked, thereby forcing twist-off only. Capremoval by pull-off may be allowed and this would typically be set to anappropriate force. It may be possible for a user to choose between bothremoval methods. The force required for cap removal by pull-off may beset at a level below that for twist off.

The removable cap may include an end cap body having at least one innersurface, which defines an axially open receiving portion, and having aninner ring, which is connected to the end cap body, wherein the innersurface of the removable end cap and the inner ring form a space forreceiving a proximal end of the longitudinal housing. This space betweenthe inner surface and the inner ring may provide a secure way in whichthe proximal end of the longitudinal housing can be received, whichreduces the risk that the cap may be misaligned or accidentally removedor knocked off. The inner ring formation in the cap is potentiallyadvantageous, but may be considered optional in relation to otherfeatures provided by the present invention.

In order to implement a suitable retaining function the retainingstructure may be formed by at least one projection, for example aU-shaped projection, formed on the outer circumferential surface of thelongitudinal housing close to the proximal end and protruding radiallyoutwards, wherein a recess of the U-shaped projection opens in distaldirection. The engaging structure may be formed by at least oneretaining rib on the radial inner circumferential surface of theremovable cap. The retaining action between the removable cap and thelongitudinal housing is provided by engagement of the retaining rib intothe U-shaped projection formed on the longitudinal housing.

A suitable retaining function may also be implemented by providing thatthe longitudinal housing and the removable cap include at least oneengagement projection and receiving formation for maintaining theremovable cap in a locked position relative to the longitudinal housing.

The longitudinal housing may include at least one radial inwardengagement projection formed on an inner circumferential surface of theproximal end of the longitudinal housing, and the engagement projectionmay be adapted to engage with at least one corresponding radial outwardprojection formed on an outer circumferential surface of the inner ring.

The at least one radial inward engagement projection may be formed by arib, preferably with a lead-in, e.g. a chamfer or a rounded edge, andthe at least one receiving formation may be formed by two opposingchamfered projections and one axial projection. The retaining elementsthat axially retain the removable cap on the proximal end of thelongitudinal housing may comprise inner protrusions formed on theproximal end of the longitudinal housing and projections formed insidethe end cap body, the projections inside the cap body comprise a recesswithin which the inner protrusion is circumferentially restrained bychamfered projections.

The cap the safety shield may, for example during removal of the cap,engage the removable cap with a proximal contact surface formed on orclose to the proximal end of the needle shield when the removable cap ismounted to the longitudinal housing. The proximal contact surface can bethe proximal front surface of the needle shield or a stepped surface orshoulder provided close to the proximal end of the needle shield. Theautomatic drug delivery device may further provide that said proximalend of the longitudinal housing engages the removable end cap upon atleast one inner surface and/or at the inner ring.

The removable cap may include at least one guiding surface or cam pathsurface which may be formed as a guiding surface inclined relative tothe longitudinal axis for guiding the removable cap in proximaldirection along at least a portion of its twisting movement. The atleast one guiding surface or cam path surface may be located at theouter circumferential surface of the inner ring. The cam path surfacemay be adapted or inclined relative to the longitudinal axis for guidingthe removable cap in a proximal direction (away from the longitudinalhousing) along at least a portion of its rotational or twistingmovement. As a further option the guiding surface may be provided as aharmonically closed curved front surface on the proximal end of theremovable housing, or formed on the inner circumferential surface of theremovable cap, wherein a corresponding guiding projection engaging theguiding surface is formed on the inner circumferential surface of theremovable cap or on the front surface of the longitudinal housing.

The safety shield may include a cylindrical and/or ring-shaped hollowbody at its proximal end, wherein at least one safety shield projectionis provided on the hollow body. The at least one safety shieldprojection may be adapted to engage with a projection or recess of theremovable cap in order to limit movement of the safety shield in thedistal direction with respect to the removable cap. Thereby, the safetyshield can be prevented from triggering the automatic drug deliverydevice unintentionally, i.e. such that it starts delivering the drug,when it is subjected to unintentional shock, particularly followingfreefall and subsequent impact with a hard surface.

The removable cap, when mounted in its retained position to thelongitudinal housing, may be secured to the longitudinal housing by arupturable seal. The rupturable seal, which may be a sticker attachedoverlapping with the outer circumferential surfaces of the longitudinalhousing and with the removable cap, may act as a visible seal showingwhether the device has already been used, if ruptured at the interfacebetween the longitudinal housing and the removable cap, or is in itsoriginal non-used state, if when intact at said interface. The rupturingof the seal may also require a certain threshold force when twisting theremovable cap relative to the housing, which may be sensed by the user.

The invention also provides a method of removing a removable cap from anautomatic drug delivery device as described herein, in which the methodcomprises:

-   -   rotating the removable cap relative to the longitudinal body to        disengage retaining elements between the cap and the        longitudinal housing;    -   providing a removal force to separate the removable cap from the        longitudinal body;    -   using the biasing force applied to the safety shield to assist        with the separation of the removable cap from the longitudinal        body.

Rotating the removable cap beyond the position in which the retainingelements between the cap and the longitudinal housing are disengaged maycause a cam path of the removable cap or housing to engage with aportion of the longitudinal housing or removable cap and provide atleast some of the removal force to separate the removable cap from thelongitudinal body.

Once the retaining elements are disengaged, the removable cap can bepushed in proximal direction by the biasing force acting on the safetyshield an audible or tactile feedback may indicates that the engagementbetween the engaging structure and the retaining structure is releasedby. Feedback may be provided by a user sensing that an initialresistance to twisting of the cap relative to the housing due to theengagement is overcome in reaction to the application of a sufficientlylarge twisting force, for example a manual twisting force. Once theengagement is disengaged by applying the sufficiently large thresholdtwisting force, the removable cap can be further rotated. After acertain level of rotation, the axial force acting on the safety shieldsupports and pushes the removable cap in proximal direction away fromthe longitudinal housing. This provides another tactile feedbackexperienced by the user which may indicate the correct way of handlingthe device.

When mounted to the proximal end of the housing, the removable cap maycontact the safety shield and hold it in a capped position such that, asthe cap is removed, the biasing force biasing the safety shield into aproximal position aids in removal of the cap. It should be noted thatthe removable cap may not be axially retained on the proximal end of thelongitudinal housing by engagement of retaining elements between the capand the longitudinal housing which can be disengaged by rotation of thecap relative to the longitudinal housing to allow axial movement of thecap relative to the housing to remove said cap.

The capped position of the safety shield may be between the proximalposition to which the safety shield is biased when unconstrained by thecap and the distal position. In this way the safety shield is held at aposition within its expected working range. As noted above, the cappedposition may be such that further displacement against the biasing forcewould be required in order to move the safety shield to the distalposition.

In the capped position the tip of the injection needle may protrudebeyond the safety shield. The cap holds the safety shield in the cappedpositon and prevents access to the injection needle. As the cap isremoved the safety shield moves to its proximal position in which itprotrudes out of the proximal end of the longitudinal housing in orderto cover a needle tip of the injection needle.

The removable end cap body may be formed to have a cylindrical bodyintegrally formed with an extension, such as an arch-like extension orlobe such that the body has a non-circular sectional form providing ananti-roll shape when the end cap is placed on a flat or slightlyinclined surface. The outer surface of the body may be textured orknurled to improve grip. For example, the outer surface of the body mayhave a number of integrally formed radial gripping recesses orprotrusions extending in a longitudinal direction between the proximaland distal ends of the body. The proximal part of the body may be formedby a smooth outer surface. This surface may include arrow-shaped throughholes, recesses or projections, or other indicia, which indicate thedirection of movement for twisting off and/or pulling the end caprelative to the longitudinal housing.

The interior of the end cap body may include a cylindrical surfaceforming an axially open receiving portion with a smooth receivingsurface. Next to the receiving portion there may be an integrally formedinner ring portion. The ring portion may include a substantially flatdistally facing surface. Between the ring portion and the innercircumferential surface of the end cap body, there may be provided oneor more open sections and one or more connecting structures connectingboth elements. The ring portion may provide on its outer circumferentialsurface one or more projections extending radially outwards into theopen sections. On both sides of the projections, the outercircumferential surface of the ring portion can be provided withinclined lifting formations which have the most distal level close tothe projections and which are inclined in a distal direction to meet onan apex.

The outer circumferential surface of the ring portion may have twoprojections with lead-ins such as a chamfer or radius, which form areceiving space there between. This receiving space may be provided toreceive and secure a projection formed on the inner circumferentialsurface of the longitudinal housing on its proximal end, in a mannerwhich is hidden when viewing and handling the device. This provides thepossibility of a hidden coupling between the housing and the removablecap, which cannot be manipulated. Moreover, re-capping of theautoinjector can be obstructed or avoided.

On its radial inner surface, the ring body may include one or moreopposite projections, protruding radially inwards. These projections areprovided for interacting with and securing corresponding radial outwardprojections formed on the outer circumferential surface of the proximalend of the safety shield.

The removable end cap body close to its proximal end may be faced withtwo annular arches arranged in opposite relation and fixed to the innercircumferential surface of the end cap body by means of a connectionportion and connecting ribs.

An end cap cover provided for the removable end cap body may have aproximal end cap portion having the same basic surface with a slightlyinclined projection as the end cap body. An annular cylindrical body mayextend from the proximal surface of the end cap portion. The annularcylindrical body may be provided on its outer circumferential surfacewith a plurality of longitudinal ribs which protrude over the distal endof the annular cylindrical body. At the free end of these longitudinalribs, snap-fit projections protruding radially outward can be provided,as far as necessary, which engage into a corresponding (annular) recesswithin the removable end cap body. The interior of the annularcylindrical body may be provided with chamfered radially extending ribsrunning into an inner cylindrical body, which is also integrally formedwith the distal surface of the end cap portion. The distal front surfaceof the arrangement formed by the cylindrical body, the projections ofthe ribs, the radially inner ribs and the inner cylindrical body canform a conical or frustoconical profile.

Gripping Element

The syringe assembly may be provided with a, preferably rigid, needleshield. The needle shield may be coupled to a proximal end of the hollowsyringe body. The needle shield may cover the needle together with its,preferably, sharpened needle tip. The inclusion of a needle shield maymean that the needle and the fluid product, e.g. the fluid medicament,are kept clean and sterile

Besides the covering function and the feedback function of the removablecap, it may have another purpose for the device. The removable cap mayalso engage a needle shield. When removing the removable cap, the rigidneedle shield may be grabbed and removed together with the cap, suchthat the user does not have to touch the rigid needle shield directly.As the injection needle and the glass body of the syringe are sensitivecomponents, the rigid needle shield has to be handled with care bothduring assembly and during removal from the syringe assembly. Theremovable cap may include a flexible gripping element for engaging theneedle shield on its outer profile.

The invention also provides an automatic drug delivery device fordispensing a fluid product, the automatic drug delivery devicecomprising:

-   -   a longitudinal housing extending along a longitudinal axis and        having a proximal end close to a dispensing site, a distal end        opposite to the proximal end and a hollow interior;    -   a removable cap mountable to the proximal end of the housing;    -   a syringe assembly arranged a mounting position inside the        housing and having a hollow syringe body and an injection needle        coupled with the hollow syringe body including the fluid        product;    -   a drive mechanism which can be triggered by a trigger element in        order to initiate dispensing of the fluid product;    -   wherein the drive mechanism is operatively coupled with a safety        shield movable within the longitudinal housing;    -   wherein the safety shield is biased into a proximal position in        which it protrudes out of the proximal end of the longitudinal        housing in order to cover a needle tip of the injection needle,        and wherein the safety shield is movable into a distal position        in which the injection needle is exposed for injection;    -   wherein the syringe assembly is provided with a needle shield        fixed to a proximal end of the hollow syringe body and covering        the needle;    -   wherein the removable cap includes a flexible gripping element        for engaging the needle shield on its outer circumferential        surface such that removal of the removable cap results in        removal of the needle shield, the flexible gripping element        having a greater diameter than a proximal end of the safety        shield.

Providing a flexible gripping element having a greater diameter than aproximal end of the safety shield allows a lower assembly force to beachieved as longer flexible gripping elements, such as legs or lobes canbe utilised. As the gripping element has a greater diameter that than aproximal end of the safety shield the gripping element may not extendinto the safety shield and this can provide packaging advantages. In theinitial capped state, with the removable cap on the device, the safetyshield may be held in a position in which at least a part of the needleshield extends beyond a proximal end of the safety shield as this mayfacilitate assembly.

The needle shield may engage the hollow conical glass portion by meansof an insert. In order to receive the needle and the needle tip in acushioning and sterile manner, the needle shield may include a softinsert receiving the injection needle. The soft insert safely covers theneedle and maintains sterility of the injection needle and themedicament contained within the syringe and the needle. The needleshield may comprise a tubular member that contains the soft insert. Theouter surface of the tubular member may include transverse gripping ribsand, or as an alternative, simply a relatively soft outer surface. Thegripping ribs, or soft outer surface, may be engaged by the grippingelement.

The needle shield may be intended to be gripped on its outercircumferential surface. The needle shield may be provided with at leastone gripping structure on its outer circumferential surface profile, forexample formed by at least one projection or a recess and engaging withthe flexible gripping element. The flexible gripping element is formedas to engage with the outer profile of the needle shield. As analternative, the gripping can be achieved by engagement of the grippingelement with the softer outer surface of an insert of the rigid needleshield.

The flexible gripping element may be fixedly mounted or may be arrangedwith axial and/or radial clearance within the removable cap. Arrangingthe flexible gripping element with axial clearance in a floating mannerwithin the removable cap facilitates flexing of the rim during assemblywhen the gripping element contacts the needle shield. The grippingelement may typically be designed to reduce forces in the axialdirection onto the rigid needle shield. This is to minimise disruptionand ensure that the container closure integrity of the pre filledsyringe is maintained. If the gripping element was rigidly held theflexing forces may be increased and axial forces onto the needle shieldfar higher. Allowing small clearance float and having an edge contact tothe gripping element are design features that reduce assembly forces andhelp to maintain container closure integrity. The clearance may alsoallow rotation of the gripping element during cap removal. This is alsoan advantageous feature reducing the potential for coring.

The flexible gripping element may be formed by a flexible washer typecomponent, for example a blade washer, having a mounting section to bemounted within the removable cap. The flexible gripping element, such asa flexible washer type component may include at least one gripping armor lobe projecting in radial inward direction for engaging the needleshield. The blade washer may have a generally frustoconical shape wheninstalled.

The flexible gripping element may have an outer circumference, forexample a circular outer circumference, surrounding a ring-shaped body.The flexible gripping element may include at least two radially inwardlyextending lobes or arms integrally formed with the ring-shaped bodywhich may end in a circular radially inner gripping feature.

The flexible gripping element may have a flat or frustoconical shape,wherein, in use, any gripping arms, or lobes, may be adapted to flex inorder to provide an axial spring action and/or a gripping force, i.e. aforce gripping the outer surface of the rigid needle shield. Such agripping force may be a force which biases the flexed gripping armstowards a radially central position and thus towards the rigid needleshield.

The external geometry of the gripping element may be of circular or anyother geometry to suit assembly loads or packaging space available.There may be two or more extending lobes formed on the radial in aportion of the gripping element and the blade geometry may be of anyformat to achieve a certain insertion forces during assembling and theability to hold forces from the rigid needle shield when the removablecap is removed from the longitudinal housing. The gripping element couldalso have some pre forming. It may be beneficial to form a rib along theouter circumference of the gripping element. This may allow rotation ofthe gripping element inside the removable cap during cap removal. If theremovable cap rotates and the gripping element is only pulledlongitudinally a detrimental condition called coring can be eliminatedthereby. Unintended coring occurs e.g. in the prior art when thematerial of the rigid needle shield is rotated around the needle hub ofthe syringe assembly. It may then be possible for an unintentionallyremoved plug of rubber to remain inside the needle, which is entirely tobe avoided in order to prevent a blockage stopping the device fromfunctioning correctly.

The removable cap may include a proximal end cap cover mountable on orinside the removable cap, wherein the flexible gripping element isarranged in a mounting space between a receiving structure formed on orwithin the removable cap end the proximal end cap cover.

The rigid needle shield may be engagable by the gripping element duringassembling with minimal resistance forces, preferably in the range of 1Nto 50 N, in axial direction applied by the gripping element.

The invention also provides method of assembling an automatic drugdelivery device as claimed in any preceding claim, the methodcomprising:

-   -   providing a power-pack subassembly, a syringe assembly, a        syringe holder, and a proximal subassembly;    -   the proximal subassembly including a longitudinal housing        extending along a longitudinal axis and having a proximal end        close to a dispensing site, a distal end opposite to the        proximal end and a hollow interior and a removable cap mounted        to the proximal end of the housing wherein the removable cap        includes a flexible gripping element and the proximal        subassembly further comprises a safety shield, wherein the        flexible gripping element has a greater diameter than a proximal        end of the safety shield;    -   the first syringe assembly comprising a hollow syringe body and        an injection needle formed with the hollow syringe body        including the fluid product, the syringe assembly being provided        with a needle shield fixed to a proximal end of the hollow        syringe body and covering the needle;    -   the power-pack subassembly comprising a drive mechanism which        can be triggered by a trigger element in order to initiate        dispensing of the fluid product;    -   mounting the syringe assembly in the syringe holder;    -   inserting the syringe assembly and syringe holder into the        proximal subassembly such that the needle shield extends through        the flexible gripping element so that the flexible gripping        element engages the needle shield on its outer circumferential        surface; and    -   mounting the power-pack subassembly to the proximal subassembly        such that the drive mechanism is operatively coupled with the        safety shield.

The removable cap may include a proximal end cap cover mountable to theremovable cap, wherein the flexible gripping element is arranged in amounting space between a receiving portion inside the removable end capand the proximal end cap cover.

The gripping element may provide an asymmetric griping force so that theneedle shield is biased to a non-aligned position, for example anon-axial alignment within the removable cap.

This may be achieved in a variety of ways, for example one or more lobesof the gripping element can have a different shape and/or length thanthe other lobes such that when engaging the rigid needle shield, thereis an asymmetric force load upon the rigid needle shield. This leads toa tilting or turning action such that the rigid needle shield isdeflected from its original position. Thereby, recapping, i.e.reattaching the cap onto the housing once it has been removed, can beobstructed or avoided.

End of Dose Features

The automatic drug delivery device may further include a feedbackmechanism providing tactile and/or audible and/or visual feedback to theuser to indicate the state of operation, wherein the feedback mechanismmay include a visual indicator, which appears within the distal end ofthe housing. The visual indicator may appear in a window which may beprovided by an aperture, or may be made of a transparent, or translucentmaterial. Said window and/or distal end of the housing may betransparent or translucent around its entire circumference such that thevisual indicator appears in an angular range of up to 360°. The windowand or distal end of the housing may be provided by the housing or by aseparate part coupled to the housing, e.g. an end cap.

The invention also provides an automatic drug delivery device fordispensing a fluid product, the automatic drug delivery devicecomprising:

-   -   a longitudinal housing extending along a longitudinal axis and        having a proximal end close to a dispensing site, a distal end        opposite to the proximal end and a hollow interior;    -   a removable cap mountable to the proximal end of the housing;    -   a syringe assembly arranged a mounting position inside the        housing and having a hollow syringe body and an injection needle        coupled to the hollow syringe body including the fluid product;    -   a drive mechanism which can be triggered by a trigger element in        order to initiate dispensing of the fluid product;    -   wherein the drive mechanism is operatively coupled with a safety        shield movable within the longitudinal housing,    -   wherein the safety shield is biased into a proximal position in        which it protrudes out of the proximal end of the longitudinal        housing in order to cover a needle tip of the injection needle,        and wherein the safety shield is movable into a distal position        in which the injection needle is exposed for injection;    -   the device further including a feedback mechanism providing a        visual feedback to the user indicating an actual state of        operation, wherein the feedback mechanism includes a visual        indicator which appears in a transparent window on the distal        end of the housing.

The the visual indicator may move distally to appear in the transparentwindow. The visual indicator may be formed by a radial inner indicatorcomponent and a radial outer indicator component biased by an indicatorspring into an indicator position. The outer indicator may be releasedinto the indication position following the delivery of a predetermineddose of the drug is delivered to a patient. The predetermined dose maybe any predetermined dose, but may be a majority of the dose, more than70% of the dose, more than 90% of the dose, or substantially all of thedose. The predetermined dose may be a sufficiently large proportion ofthe dose such that the appearance of the visual indicator is indicativeof the end of injection. The visual indicator may appear in atransparent window on the distal end of the housing to indicate the endof injection.

The outer indicator component may include a visible surface. The visiblesurface is the surface that is intended to provide the visualindication. The visible surface may include one or more of colours,shapes, patterns, symbols and images so that the visible surface can bereadily distinguished from other surfaces or components of the device.The inner indicator component may interact with the housing or aseparate part, e.g. an end cap coupled to the housing, for providing anaudible and/or tactile signal.

The device may include a distal endcap which is closed by a distalsurface. The distal endcap may be formed from a transparent material toprovide the transparent window. The distal surface may be formed from atransparent material.

The safety shield spring may be supported between a shield retentiontrigger element and a shield retention indicator member. The shieldretention trigger member may support a proximal end of the safety shieldspring and may apply the biasing force to the distal end of the, oreach, longitudinal arm of the safety shield in order to bias it inproximal direction. The shield retention indicator member may supportthe distal end of the safety shield spring.

The invention also provides an automatic drug delivery device fordispensing a fluid product, the automatic drug delivery device:

-   -   a longitudinal housing extending along a longitudinal axis and        having a proximal end close to a dispensing site, a distal end        opposite to the proximal end and a hollow interior;    -   a removable cap mountable to the proximal end of the housing;    -   a syringe assembly arranged a mounting position inside the        housing and having a hollow syringe body and an injection needle        coupled to the hollow syringe body including the fluid product;    -   a drive mechanism which can be triggered by a trigger element in        order to initiate dispensing of the fluid product;    -   wherein the drive mechanism is operatively coupled with a safety        shield movable within the longitudinal housing,    -   wherein the safety shield is biased into a proximal position in        which it protrudes out of the proximal end of the longitudinal        housing in order to cover a needle tip of the injection needle,        and wherein the safety shield is movable into a distal position        in which the injection needle is exposed for injection;    -   wherein the safety shield has at least one longitudinal arm        extending in distal direction guided within the longitudinal        housing, wherein the safety shield interacts with a safety        shield spring biasing the safety shield in proximal direction        via the at least one longitudinal arm and wherein the safety        shield spring is supported between a shield retention trigger        member and a shield retention indicator member, wherein the        shield retention trigger member supports a proximal end of the        safety shield spring and applies the biasing force to the distal        end of the longitudinal arms of the safety shield, and wherein        the shield retention indicator member supports the distal end of        the safety shield spring.

The drive mechanism may include a plunger biased by a drive spring intoproximal direction. The plunger may act on a stopper sealably guidedwithin the syringe body and acting on the fluid product included withinthe syringe body. The syringe holder may receive axial forces applied bythe plunger onto the syringe body and may transmit the forces to thelongitudinal housing.

The loaded or energized drive mechanism may include a retainer. Theretainer may extend from a distal end of the device to the syringe body.The retainer may comprise at least one flexible arm which is deformablein radial direction. The at least one flexible arm may be used forholding the plunger into a loaded position, in which it is biased inproximal direction.

The retainer may be resiliently deformable to bias the syringe body inthe proximal direction. The retainer may comprise a proximal ring-shapedhead portion having two opposing projections. The projections maycontact the syringe body and may be configured to fit within a syringebody having a larger diameter so that the proximal ring-shaped headportion contacts the syringe body. For example, the projections maycontact the syringe body of a 1 ml syringe and may be configured to fitwithin a 2 ml syringe body which has a larger diameter so that theproximal ring-shaped head portion contacts the 2 ml syringe body.

The at least one flexible arm may further be provided with a chamferedradial outward projection and a chamfered radial inward projection. Thechamfered radial inward projection may be provided to interact with acorresponding engagement surface of the plunger in order to hold theplunger in loaded position. The at least one flexible arm may interactby means of the chamfered radial outward projection with an innercircumferential surface of the shield retention trigger element.

The safety shield, when being pushed in distal direction for the purposeof initiating dispensing the fluid product, may move the shieldretention trigger element in distal direction, such that it compressesthe safety shield spring. After a predetermined stroke of the safetyshield, the shield retention trigger element may release the at leastone flexible arm for radial outward movement, whereby the plunger isreleased to move under the biasing force of the drive spring in proximaldirection in order to press out and dispense the fluid product from thesyringe body through the needle.

The shield retention indicator may include at least one longitudinalholding arm, wherein the shield retention indicator may be held by theat least one holding arm in a non-visible position, in which anindication surface is not visible through the housing (either through awindow opening, or through a transparent part of the housing. Thus theshield retention indicator provides the visual indicator. The at leastone holding arm may be held by the retainer as long as the plunger hasnot reached a predetermined dispensing position. The plunger releasesthe at least one holding arm from the retainer when reaching thepredetermined dispensing position. After release of the at least oneholding arm the shield retention indicator may be pushed by the safetyshield spring to a visible position, in which that indication surface isvisible through the housing. A tactile and/or audible signal may begenerated, when the shield retention indicator reaches its final visibleposition.

After the shield retention indicator is released and has moved to avisible position, and the safety shield has been biased to a position inwhich is covers the needle tip, the shield retention indicator mayprevent distal movement of the shield retention trigger member and theshield retention trigger member may prevent distal movement of thesafety shield. In this way a locked chain of components can be formedfrom one end of the device to the other in order to prevent movement ofthe safety shield in the distal direction.

The shield retention indicator may be formed by a hollow cylindricalbody having an annular cylindrical element, which can be extended by anarch-like extension or lobe adapted to the geometry of the housing. Itmay be received in a slidable but form-fitting manner by the extendedportion of the hollow cylindrical body of the longitudinal housing. Ithas a smooth outer circumferential surface. At its proximal end, theshield retention indicator may be provided with a plurality of,preferably four longitudinal flexible arms, each having a proximal freeend. The free ends of the flexible arms can be provided with protrusionsextending radially inwardly and reinforced by short longitudinalchamfered ribs. The distal end of the shield retention indicator can beprovided with a circular opening.

The arms of the shield retention indicator, as mentioned above areflexible and therefore dampen to a certain, very limited amount, thedegree of movement of the safety shield in distal direction after use.However, besides this slight dampening movement, these arms block thesafety shield movement in the distal direction and they are configuredto buckle radially outwards against the hollow cylindrical body of thelongitudinal housing. Thereby, the device provides a very safe lockoutafter use, preventing easy access to the needle.

The circumferential outer surface of the shield retention indicator mayhave a signalling colour, i.e. yellow, orange or red, or a signallingpattern which is clearly visible by a user. Thereby, as will bediscussed in detail in regard to the operation of the drug deliverydevice according to the present invention, the user of the autoinjector,i.e. the medical practitioner or the patient, or care giver, can easilyrecognize when the shield retention indicator is moved into a signallingposition in which it is clearly visible through the longitudinal housingfrom the outside.

The shield retention indicator inner element may be formed by a steppedtubular body having a first hollow cylindrical portion with a smallerdiameter and an enlarged second hollow cylindrical portion with a largerdiameter. At its proximal end, the shield retention indicator innerelement may be provided with two opposing flexible longitudinal armsextending in proximal direction, wherein a first portion runs inlongitudinal direction, a second portion is slightly inclined radiallyinwards, and a third portion extends in longitudinal direction, however,on a radial level which is further radially inwards than the firstportion. At its proximal end, each of the arms may have an inclinedretaining projection extending radially outwards.

The distal portion of the shield retention indicator inner element maybe provided with an end plate having about the same rounded and extendedcross-sectional surface as the distal end of the shield retentionindicator. The diameter of the outer circumferential surface of thesecond hollow cylindrical portion can be adapted to be received withinthe circular opening provided in the distal end of the shield retentionindicator.

In order to increase the safety level of the device, the device mayfurther provide a lock ring within the longitudinal housing in aninitial position. The lock ring may be locked to the safety shieldduring operation, wherein the lock ring blocks movement of the safetyshield in distal direction, when the safety shield covers the needleafter the fluid product is finally dispensed and the automatic drugdelivery device has been removed from the injection site.

The lock ring in the initial state may be held by the receivingcomponent, wherein the lock ring engages with the safety shield, afterthe safety shield has been pushed in distal direction. The lock ring ismoved with the safety shield in proximal direction under the springforce of the safety shield spring when removing the automatic drugdelivery device from the injecting side. Moreover, the lock ring mayblock any movement of the safety shield against the receiving componentin distal direction when covering the needle.

After release of the plunger from the retainer, proximal movement of thesafety shield may be prevented until the plunger reaches a predetermineddispensing position. This predetermined position may be the same as thepredetermined position in which the shield retention indicator, but neednot be the same. This may allow for accidental removal and thenre-insertion of the needle rather than accidental removal resulting thesafety shield covering the needle and thus wasting the remainder of thedose. Retaining the safety shield in a retracted state can also make iteasier for a user to hold the device against the skin as the biasingforce acting on the safety shield is not acting to move the device awayfrom the skin.

The safety shield may be pressed by the end cap via the longitudinalarms against the force of the shield spring in distal directionpartially into the housing. The trigger element may act as anintermediate element between the longitudinal arms and the shieldspring. The trigger element in the assembled state can be permanentlycoupled via its projections and any clipping features within, to thedistal ends of the arms of the safety shield. The projections can bereceived within the inner guiding profile at the distal end of thelongitudinal arms. Moreover, chamfered projections upon any clipfeatures can engage into through holes or recesses respectively, andthereby prevent, in the assembled state that the arms of the safetyshield are separated under an axial force from the trigger element. Thechambers of the projections and a guiding profile of the distal end ofthe arms facilitate the assembling process.

The proximal end of the shield spring may engage against the distalportion of the trigger element and may abut against the circumferentialor lateral ribs of the trigger element. The distal end of the shieldspring may press via the distal end of the shield retention indicatoragainst the flanged proximal surface of the plate of the shieldretention indicator inner element.

The shield retention indicator with its cylindrical body may receive andsurround the shield retention indicator inner element as well as theshield spring. The longitudinal arms of the shield retention indicatormay extend in a proximal direction through gaps provided between anylateral tabs and/or box structures, each of them may project radiallyoutwards from the trigger element. The longitudinal arms may pass thetrigger element, such that the protrusions of the shield retentionindicator arms engage the outer circumferential surface of the retainer.

The retainer and connected components may be fixedly held within thedistal end cap, for example; by the hollow cylindrical body grippingwith an inner circumferential projection into the outer circumferentialgroove of the retainer in a form-fitting manner. Thereby, the retainercan be fixed within the device against any movement in axial directionas well as against tilting.

The shield retention indicator together with the shield retentionindicator inner element may be held in the axial position by means ofthe shield retention indicator inner arms in spite of the compressedshield spring and the resulting axial drive forces. This can be achievedby the arms reaching through the longitudinal cutouts of the retainerand engaging with their radial retaining projections behind the lateralprojections of the retainer bridging the corresponding cutouts of theretainer. Moreover, in this state, the outer circumferential surface ofthe plunger arranged radially inside the arms may prevent that the armsflex radially inwards and escape from the holding function on thelateral projections.

The plunger can retain the main spring in a compressed state. Theproximal end of the compressed main spring may press against theproximal end of the plunger. The proximal end of the plunger can beslidably received within the hollow glass body of the syringe close tothe stopper element. The distal end of the main spring may protrude outof the plunger and can be received within the hollow interior of theretainer where it is supported against its distal end. The plunger canbe held in its axial position against the drive force of the main springdue to engagement between the flexible arms with the radial inwardprojections, which engage into the through holes provided in theplunger. As the flexible arms are kept in position by contact betweentheir outwardly radial projections and the inner circumferential surfaceof the trigger element, the flexible arms cannot flex radially outwardin reaction to the drive force of the compressed main spring. Thereby,the plunger is held by the flexible arms of the retainer and theirinwardly radial projections.

Platform Features

The invention also provides automatic drug delivery device fordispensing a fluid product, the automatic drug delivery device:

-   -   a longitudinal housing extending along a longitudinal axis and        having a proximal end close to a dispensing site, a distal end        opposite to the proximal end and a hollow interior;    -   a removable cap mountable to the proximal end of the housing;    -   a syringe assembly arranged a mounting position inside the        housing and having a hollow syringe body and an injection needle        coupled to the hollow syringe body including the fluid product;    -   a drive mechanism which can be triggered by a trigger element in        order to initiate dispensing of the fluid product;    -   wherein the drive mechanism is operatively coupled with a safety        shield movable within the longitudinal housing,    -   wherein the safety shield is biased into a proximal position in        which it protrudes out of the proximal end of the longitudinal        housing in order to cover a needle tip of the injection needle,        and wherein the safety shield is movable into a distal position        in which the injection needle is exposed for injection;    -   wherein the longitudinal housing provides an inner receiving        component fixed thereto for receiving a syringe holder and        providing a predetermined radial and axial position of the        syringe holder within the longitudinal housing;    -   wherein the syringe assembly is a first syringe assembly and is        received within the longitudinal housing by a first syringe        holder, wherein the first syringe holder provides an interface        between the longitudinal housing and the syringe assembly; and    -   wherein the longitudinal housing and receiving component is        sized and configured to be able to receive a second syringe        holder and a second syringe assembly, the second syringe        assembly having a different diameter than the first syringe        assembly.

This ability for the device to be adapted to a different syringediameter with the replacement of a single part, in this case the syringeholder, may allow this device to be used as a platform device for avariety of syringe assemblies. The longitudinal housing and receivingcomponent may be sized and configured to be able to receive a secondsyringe holder and a second syringe assembly, the second syringeassembly having a larger diameter than the first syringe assembly.

The inner receiving component may be fixedly mounted to the innercircumferential surface of the longitudinal housing and may provide apredetermined radial and axial position of the syringe holder within thelongitudinal housing. The syringe holder may be received with itsproximal end within the receiving component. The receiving component maybe integrally formed within the housing. Alternatively, the receivingcomponent may be formed as at least one separate piece fixedly mountedto the inner surface of the longitudinal housing.

Using a syringe holder may allow the pre-manufacture of a subassemblyformed by the syringe holder and the syringe assembly. In the subsequentassembly process, this subassembly can be used and mounted within thelongitudinal housing. This prevents that the glass body of the syringeassembly is to be directly handled during the assembling process.Instead, the syringe holder already covers, at least partially, theglass body of the syringe assembly and protects it during assembling.Moreover, the syringe holder according to the present invention isprovided to receive forces acting on the syringe assembly and totransmit these forces into the housing, wherein stresses acting on theglass body can be avoided or at least substantially reduced.

The receiving component may be formed as an annular member receivingwith its inner circumferential surface the proximal end of the syringeholder. The outer circumferential surface of the annular member may bemounted to the inner circumferential surface of the longitudinal housingby means of at least two interconnecting arms. The interconnecting armsbetween the receiving component and the longitudinal housing can beformed by a solid structure having sufficient wall thickness in order toavoid any unintended movement of the receiving structure relative to thehousing under axial loads acting thereon during operation.

The syringe holder may be further provided in a distance from itsproximal end, preferably on its distal end, with at least one contactstructure for contacting the inner circumferential surface of thelongitudinal housing. In this way, the syringe holder can be supportedin two distanced axial positions within the longitudinal housing, i.e.on its proximal front end by means of the receiving structure andmoreover by the contact structure. Thus, the syringe holder provides astabile position for the syringe assembly within the longitudinalhousing.

The contact structure may be formed by two opposite support archesextending in radial direction from the distal end of the syringe holder.A recess between the two arches can be used to guide further functionalcomponents of the trigger mechanism or the like, e.g. the longitudinalarms of the safety shield as discussed herein. The two longitudinal armsmay be guided through recesses formed in the syringe holder between thesupport arches.

As noted above, the drive mechanism may include a plunger which may bebiased by a drive spring into proximal direction. The plunger may act ona stopper sealably guided within the syringe body and acting on thefluid product included within the syringe body. The syringe holder mayreceive axial forces applied by the plunger onto the syringe body andmay transmit the forces to the longitudinal housing.

The syringe holder may resiliently engage the syringe glass body closeto its proximal end by means of at least two resilient arms. Inparticular, the syringe holder may be adapted to grip around a proximalfront shoulder of the glass body of the syringe such that the resilientarms slightly flex out during assembly and engage with the glass syringebody on a radial step surface formed radially around a needle hub of thesyringe glass body.

In order to provide the possibility of using one and the same deviceaccording to the present invention for different prefilled syringeshaving different fluid product volumes, i.e. in order to provide aplatform device usable for different prefilled syringe sizes, accordingto another aspect of the present invention the syringe holder may beprovided in different sizes adaptable to different sizes of the syringebody. Thereby, the syringe holder can be provided in differentconfigurations in order to receive different syringe sizes andaccommodate these different syringe sizes within the device according tothe present invention without the need of modifying longitudinal housingor any other component thereof.

The invention also relates to a syringe holder for an automatic drugdelivery device as described herein, wherein the syringe holder isadapted for receiving the syringe assembly within the longitudinalhousing, wherein the syringe holder provides an interface between thelongitudinal housing and the syringe assembly, wherein the longitudinalhousing provides an inner receiving component fixedly mounted to theinner circumferential surface of the longitudinal housing providing apredetermined radial and axial position of the syringe holder within thelongitudinal housing, wherein the syringe holder is received with itsproximal end within the receiving component.

The syringe holder may receive the syringe in a radial or in an axialdirection. The syringe holder may form part of the syringe assembly andmay act as an interface, spacer, or adapter, allowing variouscombinations of syringe bodies and injection needles to be used with aparticular automatic drug delivery device. In particular, the syringeholder may allow a device designed to accept a syringe body having afirst external dimension (with or without a syringe holder), to accept asyringe body having a second external dimension, which is smaller thanthe first external dimension, by changing/adding only one component. Theexternal dimension of the syringe body may be diameter, or may belength.

The syringe holder may be arranged to provide contact, interface, ormounting, points with which the syringe assembly interacts with otherparts of the automatic drug delivery device. The contact, interface, ormounting, points provided by the syringe holder may replicate contact,interface, or mounting, points of another syringe assembly, for exampleone which does not require a syringe holder, or one which includes adifferent syringe holder. In this way the automatic drug delivery devicemay be designed to receive, and interact with, a syringe assembly of afirst size and shape, perhaps without a syringe holder, and still beable to receive, and interact with, a different syringe assembly throughuse of an appropriate syringe holder.

The contact, interface, or mounting, points may be provided on anysuitable part of the syringe holder. The contact, interface, ormounting, points may be provided on one or more surfaces of one or moreflanges, ridges or other extensions from a body of the syringe holder.There may be at least two contact, interface, or mounting, points, andthese may be longitudinally separated along a length of the syringeholder. One contact, interface, or mounting, point may be located at oneend of the syringe holder and one at an opposite end of the syringeholder. As an example, the syringe holder may comprise a first interfacethat substantially replicates a flange of a syringe.

The ability of the automatic drug delivery to receive and interact witha variety of syringe assemblies is significant as it allows a singledevice design to be used to administer medicaments from differentsyringe bodies and potentially in different volumes. A plurality ofsyringe holders may be provided for the device so that an appropriatesyringe holder can be selected for use with a particular syringe bodyand needle combination.

The invention therefore further provides automatic drug delivery devicefor dispensing a fluid product, in particular a fluid medicament,including:

-   -   a longitudinal housing extending along a longitudinal axis and        having a proximal end close to the dispensing site, a distal end        opposite to the proximal end and a hollow interior;    -   a removable cap mountable to the proximal end of the housing;    -   a syringe assembly arranged a mounting position inside the        housing, the syringe assembly having a hollow syringe body and        an injection needle coupled with the hollow syringe body, the        hollow syringe body containing the fluid product;    -   a drive mechanism which can be triggered by a trigger element in        order to initiate the dispensing of the fluid product;    -   wherein the loaded drive mechanism is operatively coupled with a        safety shield movable within the longitudinal housing,    -   wherein the safety shield is biased into a proximal position in        which it protrudes out of the proximal end of the longitudinal        housing in order to cover a needle tip of the injection needle,        and wherein the safety shield is movable into a distal position        in which the injection needle is exposed for injection;    -   wherein the syringe assembly further comprises a syringe holder,        the syringe holder supporting the syringe body within the        housing.

The invention further provides a method of manufacturing an automaticdrug delivery device comprising the steps of:

-   -   providing a housing, a drive mechanism and a safety shield;    -   providing a hollow syringe body and an injection needle coupled        with the hollow syringe body, the hollow syringe body containing        a fluid product;    -   determining whether a syringe holder is required to support the        hollow syringe body and injection needle combination;    -   if necessary, selecting an appropriate syringe holder and        creating a syringe assembly comprising the syringe holder,        hollow syringe body and injection needle; and    -   installing the drive mechanism, safety shield and syringe        assembly into the housing to create the automatic drug delivery        device.

A plurality of syringe holders may be provided. Syringe holders may beconfigured in different geometries and adapted to receive differentsyringes with different volumes of medicament, wherein, independent fromthe received syringe, the respective syringe holder is adapted to fitinto the same housing of said automatic drug delivery device. In otherwords, a syringe holder according to the invention can be provided indifferent geometries and with different structures such that it receivesdifferent syringe sizes (e.g. 1 ml and 2 ml) in a way that is easy andconsistent to assemble and that holds the syringe safely within thehousing. In particular, the different syringe holder geometries areadapted to fit in one and the same housing without further modification.This allows for providing a platform system, i.e. drug delivery devicewhich has the same outer dimensions, and assembly requirements fordifferent doses and medicaments. It may be necessary to replace also theplunger or provide an adapting member at the proximal plunger end, e.g.adapted to the different inner diameter of the syringe and/or thesyringe stopper.

The syringe holder may include at least one flexible portion allowingfor elastic deformation in circumferential or radial direction. This mayallow the syringe holder to receive and resiliently retain a syringebody and/or injection needle within the syringe holder.

The syringe holder may include a longitudinal body, which at itsproximal end and or at its distal end is formed with a rigid andsubstantially non-elastic U-shaped element, such that a prefilledsyringe can be introduced into the syringe holder from radial directiontransverse to the axial direction.

The syringe holder may be formed by two longitudinal shells, connectedby at least one flexible V-shaped portion, which provides flexibility ina circumferential direction to the syringe holder and allows that theshells move elastically apart when introducing a syringe.

The syringe holder may include a radial inner projection for supportingthe syringe body in the axial direction, in particular in proximal axialdirection. The radial inner projection of the syringe holder may supporta proximal shoulder of the syringe body.

The syringe assembly may include a, possibly rigid, needle shield fixedto a proximal end of the hollow syringe body and covering the needle.The syringe holder may receive the syringe assembly in a radialdirection such that the radial inner projection is located between thesyringe body and the needle shield. The radial inner projection may havea smaller diameter then the rigid needle shield.

The syringe holder may be provided with one, two or more flexible zonesor portions, in particular z-shaped flexible portions, which can flex ina radial and/or circumferential direction. The flexible portions/zonescan support the syringe in axial direction once plugged-in from distaldirection and received therein whilst allowing some degree of axialmovement e.g. for absorption of impact energy and assembly misalignment.

The drive mechanism may retain the plunger in an initial positionthrough the engagement of a radial inward projection with a slot in theplunger. The plunger may be provided with a plurality of retaining slotsadapted to different syringe sizes or variant fills. The plurality ofretaining slots may include slots at different axial positions. One ormore of the retaining slots may engage with the drive mechanism andthereby determine the initial position of the plunger relative to amoveable stopper, or other feature, of the syringe assembly. Byproviding slots having different longitudinal positions it allows theplunger to engage with the drive mechanism at different longitudinalpositions during manufacture. The plunger may comprise retaining slotsthat are longitudinally and circumferentially offset. This mayfacilitate manufacture as the slots may only engage with the drivemechanism in a particular rotational orientation. By circumferentiallyoffsetting the slots the plunger can be aligned with the drive mechanismfor assembly, rotated into the correct orientation so that thelongitudinal slots at the desired position align with the drivemechanism engagement parts. The plunger can then be assembled by alinear motion into the drive mechanism so that the desired slots engagewith the drive mechanism. If the slots were not circumferentially offsetthe assembly motion may be move complex with linear and rotationrequired and this may result in assembly errors.

The plunger may include an alignment marker to facilitate rotationalalignment. The alignment marker may be any suitable marker, for examplea visible mark, for example one that may be printed or etched one theplunger, of the marker may be a physical marker, for example aprojection or groove which can be engaged by assembly apparatus. Thealignment marker may be an alignment slot in an end of the plunger. Thealignment slot may extend entirely across a diameter of the end of asubstantially cylindrical plunger. The alignment slot may be in astopper engaging end, or plunger head, of the plunger to facilitateassembly.

The plunger head of the plunger rod may include an adapter to increasethe diameter of the plunger head for some stopper diameters. The plungeradapter may be integrally molded with the plunger. As with the syringeholders the various options can mean that a plurality of plungers areavailable for assembly into a particular device.

This means that the method of manufacturing an automatic drug deliverydevice mentioned above may further comprise the step of determiningwhich plunger head size is required for a particular syringe body andinjection needle combination and selecting an appropriate plunger forassembly into the device. The selection may not be purely based on headsize, so the manufacturing method may comprise the step of:

-   -   determining which of a plurality of plungers is required for use        with selected syringe assembly;    -   assembling the selected plunger into the device.

If the plunger has longitudinally offset slots for engaging with thedrive mechanism the method of manufacturing an automatic drug deliverydevice mentioned above may further comprise the step of determiningwhich of the longitudinal slots should engage with the drive mechanism aparticular syringe assembly and engaging an appropriate longitudinalslot with the drive mechanism during assembly. If the longitudinal slotsare circumferentially offset, the method may further include the step ofrotating the plunger to a predetermined rotation relative to the drivemechanism prior to assembly.

As noted above, the provision of a plurality of plungers and syringeholders for a particular device design can provide a platform devicewhich can be used to delivery medicament from a plurality of syringebodies having different sizes and fill volumes.

The invention therefore provides a kit of parts for assembling anautomatic drug delivery device for delivering medicament from a hollowsyringe body having an injection needle coupled thereto, the hollowsyringe body containing a fluid product, the kit comprising a standardhousing, a standard drive mechanism and a standard safety shield, aplurality of syringe holders and/or a plurality or plungers. This meansthat a combination of parts can be assembled together to create anautomatic drug delivery device that is appropriate for the particularhollow syringe body and injection needle. This ‘platform’ typearchitecture allows the device to be adapted for use with syringebody/needle combinations having different sizes/shapes/fill volumes bychanging only one or two parts.

The invention also provides a kit of parts for assembling an automaticdrug delivery device as described herein, the kit comprising apower-pack subassembly, a first syringe assembly, a second syringeassembly, and a proximal subassembly;

-   -   the proximal subassembly including a longitudinal housing        extending along a longitudinal axis and having a proximal end        close to a dispensing site, a distal end opposite to the        proximal end and a hollow interior and a removable cap mounted        to the proximal end of the housing;    -   the first syringe assembly comprising a hollow syringe body and        an injection needle formed with the hollow syringe body        including the fluid product;    -   the second syringe assembly comprising a hollow syringe body        having a diameter larger than the diameter of the syringe body        of the first syringe assembly, and an injection needle coupled        to the hollow syringe body including the fluid product;    -   the power-pack subassembly comprising a drive mechanism which        can be triggered by a trigger element in order to initiate        dispensing of the fluid product;    -   a first syringe holder to provide an interface between the        longitudinal housing and the first syringe assembly; and    -   a second syringe holder to provide an interface between the        longitudinal housing and the second syringe assembly; wherein    -   the assembled automatic drug delivery device comprises the        power-pack subassembly and the proximal subassembly and either        the first syringe assembly and the first syringe holder, or the        second syringe assembly and the second syringe holder.

The invention also provides a method for assembling an automatic drugdelivery device using a kit of parts as described above, in which themethod comprises:

-   -   selecting either the first syringe assembly and the first        syringe holder, or the second syringe assembly and the second        syringe holder;    -   mounting the selected syringe assembly in the selected syringe        holder;    -   placing the syringe and syringe holder into the proximal        subassembly; and    -   assembling the power pack subassembly onto the proximal        subassembly.

As discussed herein, the syringe holder has the purpose to receive andhold a prefilled syringe within the housing. It is adapted to receivedifferent kinds of syringes with different volumes of medicament withoutthe need of changing the other components of the subassembly. Therefore,different syringe holders are to be provided in adaptation to thedifferent kinds/volumes of syringes.

The syringe holder may comprise a longitudinal body. At its proximalend, the syringe holder may be formed with a substantially rigid andnon-elastic U-shaped element. The U-shaped element may be open in oneradial direction. This rigid U-shaped element at the proximal end may bereinforced by parallel surrounding ribs. At the proximal front surface,the U-shaped element may be provided with transverse ribs orprojections. At its distal end, the syringe holder may be provided witha substantially rigid and non-elastic similar U-shaped element. Thedistal U-shaped element may be reinforced with surrounding ribs. Thesurrounding ribs may be provided with cutouts, facing radially outwardson opposite positions. The rigid U-shaped elements may be connected bytwo, possibly substantially rigid and longitudinal, connecting arms.Each of the connecting arms may extend in a linear manner. Each of thearms may include a projection projecting radially inwards to releasablyretain a syringe in the syringe holder, the arms being deformable toallow a syringe body to pass between the projections. The inner surfaceof the projections may be profiled such that a glass body of the syringecan be arranged and held therein.

When placed within the longitudinal housing, the syringe holder holdinga prefilled syringe assembly, may be positioned such that anyprojections engage into matching cutouts of the double-ring structure.The syringe holder may be positioned by the ring structure ordouble-ring structure within the longitudinal housing in an appropriateaxial and rotational position around the longitudinal axis.

According to some examples of the syringe holder, the syringe holder canbe formed by two or more longitudinal shells, with a longitudinal slitbetween them. The shells can be connected by flexible V-shaped portions,on the distal and the proximal regions respectively, which provideflexibility in circumferential direction to the syringe holder andthereby allow that the shells move elastically apart when introducing asyringe. The syringe holder may further comprise at its distal end andclose to its proximal end radially outward projecting structures forfixing the syringe holder within a housing of an autoinjector.

An inner radial projection can be formed within both shells, forsupporting the syringe in axial direction once inserted from the distaldirection and received within the syringe holder.

Alternatively, the syringe holder may have a hollow cylindricalreceiving tube with a distal end and a proximal end. Similar to theother examples described herein, this syringe holder may also includeradial outwardly projecting structures in order to hold the syringeholder within a housing of an autoinjector.

Close to its proximal end, the syringe holder can be provided with oneor more double-z portions, which include inclined flexible armsinterconnected by a circumferential rib. At its inner circumferentialsurface, the syringe holder includes a radially inward projection, whichcan be formed circumferentially within both flexible double-z portionsfor supporting the syringe in axial direction once inserted from thedistal direction and received therein. In this syringe holder example,the syringe is pushed-in from its distal end with minor radial playwithin the hollow cylindrical receiving tube. For gripping the proximalfront end of the glass body of the syringe, due to the elasticflexibility of the two double-z portions, the arms slightly flex-outsuch that the circumferential ribs move radially outwards.

Examples for the syringe holder described herein have acircumferentially closed structure with features providing someflexibility in radial or circumferential direction. Thereby, it ispossible to provide an easy assembling of the prefilled syringe with thesyringe holder. The syringe is held simply by flexing elements whichdeform radially outwards during assembly. Thereby, tolerance variationsof the syringe assembly can be compensated both radially as well asaxially. Nevertheless, the syringe holder has a robust structure byvirtue of the rigid shells or the cylindrical receiving tube.

The plunger may be formed by a longitudinal cylindrical hollow elementwhich has at its proximal end a plunger head. The plunger head may beprovided with a front surface and a transverse slot. The front surfacemay include a small cylindrical through hole. The front surface with theoptional transverse slot and the cylindrical through hole can be coupledwith or formed with a larger diameter plunger head element, if needede.g. for syringes having a larger inner diameter interacting with acorrespondingly large stopper. This additional enlarged plunger headfeature can be used for larger syringes, e.g. suitable for a fluidvolume of 2.25 ml. In case of smaller syringes, e.g. suitable for afluid volume of 1 ml, the enlarged plunger head component or feature isomitted and the plunger has a simple parallel cylindrical shape on itsproximal end.

In the middle portion of the plunger, a pair of opposing rectangularthrough holes may be provided in the wall of the hollow element. Itshould be noted that a pair of through holes, or slots, is not required,a single through hole can be used. The plunger may have additionalthrough holes, or pairs of through holes, comparable to the throughholes, at different axial positions which allow an adaptation todifferent syringe sizes or filling volumes of the drug. At the distalend, the hollow element may be provided with a circular openingproviding access in longitudinal direction for receiving the drivespring. The proximal end of the hollow element may comprise the stopperengaging end, or plunger head as discussed above and may include arotational alignment feature.

The retainer may act as the control member for a plurality of controlfunctions of the power-pack. The retainer may be formed from a hollowcylindrical body. On two opposing sides the cylindrical body may includea U-shaped cutout forming a longitudinal flexible arm, respectively. Thelongitudinal flexible arm may be integrally connected to the hollowcylindrical body at its distal end. At its proximal end, the flexiblearm can be provided with a chamfered feature, projecting radiallyoutwards projection and, on the opposite side, i.e. on its radial innerside, a corresponding chamfered feature, projecting radially inwards.Moreover, the cylindrical body can be provided with two opposinglongitudinal cutouts in an area rotated by 90° relative to the flexiblearms formed by the cutouts. The longitudinal cutouts may extendapproximately with the same longitudinal extension as the U-shapedcutout, or further, in distal direction. In the region of about onethird of the longitudinal length of the cutouts close to their proximalend, the cylindrical body may comprise lateral projections transverselybridging the cutouts. These lateral bridging projections are continuedclose to the proximal end by additional projections having the sameouter circumferential shape.

At its proximal end, the cylindrical body of the retainer may beprovided with two or more flexible arms integrally formed with thecylindrical body and inclined at an angle relative to the proximal frontsurface of the hollow cylindrical body. These flexible arms can beconnected to a ring-shaped head portion. The ring-shaped head portioncan be formed as a bushing with a cylindrical portion and two opposingproximal arch-like projections. The head portion can be integrallyformed with the flexible arms or formed as a separate piece fixedlyconnected to the flexible arms, e.g. by means of an intermediateconnecting ring.

The flexible arms allow for certain degree of tolerance and compensationfor different syringe sizes. Moreover, these flexible arms bias thesyringe axially in the proximal direction by acting on the distal end ofthe syringe to keep it in a more or less fixed position. Conversely, thebiasing element ensures the retainer and connected components are biaseddistally.

At its distal end, the cylindrical body of the retainer can be formedwith a circumferential groove. The distal end may be provided with adistal end surface having a central opening. In its interior close tothe distal end, the cylindrical body can be provided with inner guidingribs running in axial or longitudinal direction between the distal endsurface and the longitudinal section having the circumferential groove.The cylindrical body may have varying diameters, blended accordinglybetween the diameter sizes for the purposes of assembly within theconfines of other system components arranged or connected concentricallyaround the retainer.

Moreover, the safety shield is held in the assembled initial state bythe removable cap in the axial position. In particular this has thepurpose to avoid unintended movement in distal direction, i.e. if thedevice is dropped and experiences a shock when it falls on the ground.This is achieved by an engagement between the projections formed on theouter circumferential surface of the cylindrical body at the proximalend of the safety shield and the two projections formed on the innercircumferential surface of the inner ring portion of the removable capbody. Thereby, the projections can block any axial movement of thesafety shield in distal direction relative to the removable cap mountedto the housing and thereby relative to the housing.

At the distal end, the distal end cap can be fixedly and inseparablyattached by the snap-fit arrangement to the longitudinal housing,wherein the projections formed on the outer circumferential surface ofthe skirt portion of the distal end cap engage into and with the throughholes formed on the distal end of the housing.

Moreover, in the assembled state, the syringe can be held within thesyringe holder, which is received in the ring structure of the housing.As described above, the syringe holder can be positioned relative to thehousing by means of the ring structure, wherein the transverseprojections can engage into respective cutouts and a further projectionmay project into the hollow space provided by the U-shaped element ofthe syringe holder. The syringe may be assembled in an axial or lateraldirection into the syringe holder before assembly of the syringe holderinto the housing or following assembly of the syringe holder into thehousing depending on the syringe geometry. Any U-shaped element of thesyringe holder is intended to be rigid and do not flex-out duringassembly of the syringe for the purposes of allowing the rigid needleshield to pass through or during operation. It is to be noted that thesyringe can be held rotationally within the syringe holder or can beallowed to rotate freely.

Assembling the syringe inside a device can be problematic with glassbreakage and difficulty to check final position. With the side loadingof the syringe to the syringe holder better control and access tocritical features can be achieved. Assembly may be by visual positioningand checking. Assembly may be performed by dimensional and force controland checking.

Moreover, the syringe together with the syringe holder can be pressedvia the syringe flange by means of the head portion of the retainer inproximal direction against the conical and stepped ring structure of thehousing, wherein, once fully assembled with the power-pack, the flexiblearms of the retainer act as axial biasing means providing a spring forceaxially in the proximal direction, in order to hold the syringe in placewithin the syringe holder and positioned thereby.

Further Features

The syringe assembly may comprise a hollow syringe body containing thefluid product and an injection needle formed with the hollow syringebody. It should be understood that the term hollow syringe body isintended to include a hollow cartridge or other hollow body within whicha piston, or movable stopper, can be moved to create a variable volumechamber from which fluid can be expelled via an outlet. The outlet maycomprise an integral injection needle, such as those found in a stakedneedle syringe, or the injection needle may be coupled to hollow body inanother way, such as luer lock, screw connection or other suitableconnection. It is also possible that the outlet from which the fluid canbe expelled is created during the actuation of the automatic drugdelivery device, for example by a rear portion of the injection needlepuncturing a membrane.

The housing in a cross-section of at least a portion of the housing mayhave a non-circular shape to provide an anti-rolling function. Thehousing may be formed by an opaque or a transparent material in whole,or in part.

The fluid product is typically a pharmaceutical composition/formulationsuitable for parental administration to a human or animal subject. Thepharmaceutical composition/formulation comprises one or morepharmaceutically active substances, including low molecular weightcompounds and/or biopharmaceuticals, such as recombinant products.Examples of pharmaceutically active substances include antibodies (fulllength or active fragments thereof), polypeptides/peptides andderivatives therefore, as well as nucleic acid molecules, which may bepart of vectors, viral particles, optionally in combination withdelivery vehicles such as lipids. Nucleic acids andpolypeptides/peptides may be produced by biological processes orsynthetically. In one example the fluid product comprises apharmaceutically active substance selected from secukinumab, cankinumab,bimagrumab, omalizumab, tesidolumab, iodelcizumab, elgemtumab,lacnotuzumab, ofatumumab, ligelizumab, ranibizumab, brolucizumab andianalumab.

The present invention also relates to an automatic drug delivery device,in particular an autoinjector, for dispensing a fluid product, inparticular a fluid medicament, including:

-   -   a longitudinal housing extending along a longitudinal axis and        having a proximal end close to the dispensing site, a distal end        opposite to the proximal end and a hollow interior;    -   a removable cap mountable to the proximal end of the housing;    -   a syringe assembly mounted in a mounting position inside the        housing and having a hollow syringe body and an injection needle        integrally formed with the hollow syringe body including the        fluid product;    -   a loaded or energized drive mechanism which can be triggered by        a trigger element in order to initiate the dispensing of the        fluid product;    -   a feedback mechanism providing a tactile and/or audible and/or        visual feedback to a user indicating an actual state of        operation;    -   wherein the injection needle protrudes with a sharpened needle        tip out of the proximal end of the housing when the syringe        assembly is in its mounting position;    -   wherein the loaded or energized drive mechanism is operatively        coupled to a safety shield movable within the longitudinal        housing,    -   wherein the safety shield is a biased into a proximal position        in which it protrudes out of the proximal end of the        longitudinal housing in order to cover the injection needle with        its sharpened needle tip, and wherein the safety shield is        movable against a biasing force into a distal position in which        the injection needle with its sharpened needle tip is exposed        for injection;    -   wherein during use the automatic drug delivery device comprises        the following operational states:    -   an initial state, in which the automatic drug delivery device is        fully assembled and the removable end cap is mounted to the        longitudinal housing;    -   a ready to use state, in which the removable end cap has been        removed from the housing and a safety shield covers the needle        tip;    -   a triggered state, in which the automatic drug delivery device        is being pushed against a patient's skin, thereby the safety        shield is being pushed into the longitudinal housing and        releases the needle tip for injection;    -   a dispensing state, in which the fluid product is being        dispensed into the patient's tissue; and    -   a used state, in which the fluid product has been fully        dispensed, the automatic drug delivery device has been removed        from the patient's skin and the safety shield covers the needle        tip.

The safety shield may be provided with at least one, possibly two,longitudinal arms extending in the distal direction guided within thelongitudinal housing. The safety shield may interact with a safetyshield spring which biases the safety shield in the proximal directionvia the, or each, longitudinal arm. This may allow for a relative simpleand compact triggering mechanism. The basic mechanical triggering andbiasing functions can be concentrated on the distal end of the housingapart from the safety shield and the syringe assembly.

The loaded or energized drive mechanism may include a plunger biased bya drive spring in proximal direction. The plunger may act on a stopperwhich may be sealably guided within the syringe body. The plunger mayact on the fluid product included within the syringe body.

The proximal end of the drive spring may act on a distal end of theplunger. The distal end of the drive spring may act on a fixed end capwhich may be fixed to the distal end of the longitudinal housing. Thefixed end cap may include a rod member for guiding the drive spring inlongitudinal direction. The fixed end cap may also be mounted to thelongitudinal housing by a snap-fit engagement.

The distal end of the drive spring together with the distal end of theplunger may be received within a rotary click element rotatably arrangedwithin the fixed end cap. The rotary click element and the fixed end capmay provide engaging and corresponding saw-tooth profiles permitting arelative rotation of the rotary click element relative to the fixed endcap in one rotary direction and preventing a relative rotation in theopposite rotary direction. The rotary click element may be settable inits axial position depending on the rotary position of the rotary clickelement relative to the fixed end cap. Depending on the initiallyselected rotational position of the rotary click element the intensityof an audible or tactile signal can be chosen.

The autoinjector according to the invention may be formed by differentsubassemblies, e.g. a proximal subassembly including the end cap, aprefilled syringe unit, and a power-pack subassembly. These threesubassemblies may be provided as separate pre-assembled modules forassembling the device according to the invention. This allowspre-assembly of the syringe unit and the power-pack. Moreover, acorresponding prefilled syringe can be used with a demanded medicamentprovided therein in a sealed manner and with the predetermined volumefor drug delivery.

The three subassemblies can be assembled to form the completeautoinjector by insertion of the prefilled syringe into the syringeholder (if required) within or without the syringe unit and thereafterplugging the power-pack, from the distal side, into an open distal endof the body of the syringe unit until it locks into a predeterminednon-separable position. By this modular structure, the device accordingto the invention can be easily assembled in an error-free manner. Itshould be understood that the term prefilled syringe unit, or prefilledsyringe, is being used herein to refer to a syringe body which iscoupled to an injection needle. The syringe body comprises a variablevolume chamber filled with a medicament that can be expelled through theinjection needle.

If necessary, the syringe may be attached, or coupled, within or outsidethe housing to a syringe holder to provide the syringe assembly, orsyringe subassembly.

The proximal syringe unit subassembly may comprise the removable end capformed by an end cap body, a blade washer and a proximal end cap cover.Moreover, the proximal syringe unit subassembly may comprise a safetyshield, a longitudinal housing and a syringe holder.

The syringe subassembly may include a rigid needle shield with aninsert, a glass body with a staked needle, a medicament and a stopper.

The power-pack subassembly may include a trigger element, a triggerspring, a shield retention indicator, a plunger, a drive spring, aretainer, a shield retention indicator inner element and a distal endcap.

The plunger may have a proximal end, wherein the proximal end isadaptable to suit to different syringe sizes, preferably by beingcoupled with an adaptor piece.

The device may have a label on the outside of the housing, wherein thelabel comprises a black internal surface which restricts light and theability to see the end of use indicator before use. The device may havea label on the outside of the housing which is either opaque and therebyprevents the ability to see the end of use indicator before use, or issufficiently opaque to restrict the ability of the user to see the endof use indicator prior to use.

The safety shield may include a ring-shaped hollow cylindrical body atits proximal end with two diametrically opposing longitudinal arms. Thisarrangement of the body and the longitudinal arms can be integrallyformed or formed from separate pieces, i.e. the cylindrical body mayinclude a separate cover which can be formed from a coloured material.

The ring-shaped body may have one or more projections close to itsdistal end. The distal end of the ring-shaped body may be provided withan annular collar having a rounded outer circumferential ring with oneor more opposite slots. A longitudinal hollow portion may extend fromthis annular collar in distal direction, divided by the slots in twoseparate halves. The two longitudinal arms can be integrally formed withthe distal end of the collar and have a stepped course, such that afirst transition between the collar and a first longitudinal arm portionforms a first shoulder and wherein a second transition between the firstlongitudinal arm portion and a second longitudinal arm portion forms asecond inclined shoulder. Each of the second longitudinal arm portionsmay have on its outer circumferential surface a projection protrudingradially outwards and having a sharp radial surface facing in proximaldirection and an inclined chamfered surface facing in distal direction.In line with the projection the longitudinal arm portion has a rectanglea through hole close to its distal end.

The outer circumferential surface of each second longitudinal armportion may include an inner guiding projection. Moreover, the innercircumferential surface of the cylindrical body may include guiding ribsprotruding radially inwards. These inner guiding ribs can be providedfor guiding the rigid needle shield during syringe assembly. As analternative, the outer circumferential surface of each secondlongitudinal arm portion may have guiding ribs and the innercircumferential surface of the cylindrical body may include a guidingprojection.

The cylindrical body may be smoothly formed and chamfered on its front(proximal) end such that it does not injure or scrape on the patient'sskin. As mentioned above, the cylindrical body, together with thelongitudinal arms, may be a single-piece arrangement or a multi-pieceassembly.

The housing has the purpose of forming the main body of the device. Itis formed from a stable, rigid, transparent or opaque material. If notentirely transparent, the housing can be formed with drug viewingcutouts or transparent windows in order to allow the liquid contents ofthe syringe, and the state of the device visible to a user.Additionally, or alternatively, the position of the stopper may bevisible to a user through such windows. The state of the device mayinclude the position of the stopper within the syringe body. The housingis formed by a longitudinal tubular member. At its proximal end, thetubular member may be provided with a hollow cylindrical portion havinga generally circular cross-section and a front surface. At a distancefrom the proximal end, the longitudinal member can be provided with anarch-like extension or lobe, having the same general shape andcross-section as the end cap cover, in order to provide further geometrywith an anti-roll function on a flat surface e.g. for when the removableend cap is removed.

At the proximal end of the housing, the cylindrical portion may beprovided on its circumferential inner surface with rib-like opposingprojections, protruding radially inwards, which may be hidden orobscured to the outside, and which are adapted to interact with theremovable end cap. Moreover, in its middle section, the housing may beprovided with two opposing longitudinal through holes, having thefunction of guiding slots. As an alternative, these through holes can bereplaced by guiding channels which open to the inside of the housing,but which are closed on the outer circumferential surface thereof. Inline with the guiding slots but closer to the distal end, the housingmay be provided with further opposing through holes, which as analternative can be also provided as internal recesses which are closedat the outer circumferential surface. Close to its distal end, thehousing may be provided with a pair of opposing transverse throughholes, which as an alternative can be also provided as internal recesseswhich are closed at the outer circumferential surface, for the purposeof attachment to the power-pack subassembly. The distal end may befurther provided with a distal front surface, which has two opposingshort notches for the purpose of enhancing rotational coupling with thepower-pack.

In its interior, the housing may be provided with a ring or double-ringstructure, which is integrally connected to the tubular member in theregion of the cylindrical portion by means of at least one rigidconnecting arm. The connecting arm can be formed by a stable U-shapedstructure with two lateral longitudinal connecting ribs and onetransverse connecting rib running in circumferential direction. The sizeof the connecting ribs and the U-shaped sectional shape are to providestructural rigidity to the housing. This joining geometry is alsoimportant for the flow of the material when the component is molded.

Moreover, the ring structure or double-ring structure may have an outerring running with a conical transition portion into a hollow inner ring.To the proximal end, strengthening ribs may stabilize the connectionbetween the outer ring and the inner ring. At the distal end, theconical transition portion may be provided one or more cutouts and/orrib-like axial projections. The arrangement of the cutouts and the axialprojections may be provided for positioning the prefilled syringedirectly, or in connection with a syringe holder.

The trigger element may be formed by a broadly cylindrically shapedhollow body. At its proximal end it has a front surface surrounded by achamfered rim and provided with two opposite lateral tabs extending inthe radial direction. From the front surface of these lateral tabs tworectangular projections may extend in longitudinal axial direction. Theprojections can be provided with chamfered projections, extendingradially outwardly for biasing of the safety shield. The tube shapedhollow body may extend in the distal direction and provides, in itsmiddle portion, a surrounding annular reinforcement rib connected to thereinforced proximal end by longitudinal ribs. Between the proximal endand the reinforcement rib, two opposing rectangular hollow box elementsor recesses formed by other wall structures may be provided at the outercircumferential surface of the trigger element, wherein these boxelements or recesses provide a hollow space, respectively, in whichadditional components, e.g. electronic sensors or the like can beprovided. The trigger element acts as a temporary blocking element forthe shield retention indicator described below during use of the drugdelivery device.

Further in the distal direction, the outer circumferential surface ofthe tubular hollow body can be provided with a further annular andcircumferential reinforcement rib, e.g. having an L-shaped profile tosupport the spring. The distal end of the tubular hollow body of thetrigger element can be formed by a hollow cylindrical portion having afront surface. In its interior, the trigger element may be provided witha plurality, preferably four longitudinal guiding ribs, wherein twopairs of these guiding ribs are connected by an arch-like connectingrib, respectively, which extends in circumferential direction along theinner circumferential surface of the tubular hollow body.

The end plate may obscure easy viewing of the indicator coloured surfacewhen a label is on the outer surface of the transparent housing.

The shield spring biasing the shield retention indicator inner elementin the distal direction can be arranged in a hidden way between theshield retention indicator inner element and the shield retentionindicator. The whole indicator arrangement can be arranged at the distaland portion of the drug delivery device, which, in use, faces the userand is easily visible.

The distal end cap may have a distal end cap body having the samecross-sectional profile as the distal end of the longitudinal housing,i.e. rounded with an arch-like extension or lobe. The distal end capbody may be formed from a transparent material and closed by a distalsurface. A transition between the circumferential surface and the distalsurface can be rounded or chamfered. At its proximal end, the distal endcap may be provided with a skirt portion, which can be form-fittinglyreceived in an assembled state within the distal end of the longitudinalhousing. Therefore, the skirt portion has a reduced outer diameter andtransitions to the distal end cap body via a stepped surface.

In the region of the stepped surface the distal end cap may providelongitudinal protrusions corresponding to the notches described for thelongitudinal housing. By interaction of the protrusions and the notches,the distal end cap can be positioned relative to the longitudinalhousing. Moreover, the skirt portion may be slotted to provide two ormore longitudinal projections. The outer circumferential surface ofthese longitudinal projections is formed with chamfered snap-fitprojections, respectively. These projections are provided to engage in asnap-fit manner with corresponding through holes provided in thelongitudinal housing when assembling the device.

It is to be mentioned that the snap-fit engagement between theprojections and the through holes—once assembled—should not be easilyseparable. The device according to the present invention is a single usedevice and excludes that the distal end cap, after having been fixed tothe longitudinal housing, is removed from the housing again. It is notprovided or intended to replace or refill the syringe after use or toprovide any other access to the interior and the components of thedevice, once it has been used.

Turning to the interior of the distal end cap, the end cap may beprovided with a hollow cylindrical body integrally formed with a bottomsurface of the distal end cap. Preferably, the distal end cap is formedby a transparent or opaque material providing a 360° window for showingthe indicator in a used state of the device. In its interior, the distalend cap includes a hollow receiving portion, e.g. a cylindrical hollowbody, for receiving the distal end of the drive spring received withinthe distal end of the retainer. However, by choosing a neutral colourfor the retainer, this arrangement is not visible from the outsidethrough the transparent distal end cap.

In the assembled or initial state of the device, the end cap is attachedonto the longitudinal housing, wherein the end cap is held incircumferential direction by an engagement of each of the innerprotrusions formed on the proximal end of the housing within acorresponding receiving space between the two projections formed insidethe end cap body. Moreover, the end cap can be held in longitudinaldirection by an engagement of each of the inner protrusions formed inthe proximal end of the housing located behind the projections formed onthe inner ring portion of the end cap body, respectively. Thereby, theremovable cap can be held on the housing against an axial withdrawingforce by the projections as well as against small twist-off forces,which are below a twist-off force threshold value, by the opposingprojections forming the receiving space.

The longitudinal housing may be formed by a transparent or opaquematerial, having at least a transparent portion or window through whichan actual state of operation is visible to a user.

DETAILED DESCRIPTION

The invention will be further describe by way for example only withreference to the following figures in which:

FIG. 1 is a perspective view of a drug delivery in an assembled state;

FIG. 2 is an exploded view of the drug delivery device according to FIG.1 showing subassemblies thereof, in particular a removable cap, a safetyshield, longitudinal housing and a syringe holder;

FIG. 3 an exploded view of the drug delivery device according to FIG. 1showing subassemblies thereof, in particular the prefilled syringe;

FIG. 4 is an exploded view of the drug delivery device according to FIG.1 showing subassemblies thereof, in particular a trigger element, atrigger spring, a shield retention indicator, a plunger and a powerspring, a retainer, a shield retention indicator inner, and a distal endcap;

FIGS. 5 to 7 show different perspective views of a cap housing and FIGS.8 and 9 show different perspective views of a cap insert;

FIGS. 10 to 13 show different perspective views of examples of a needleshield gripper;

FIGS. 14 to 18 show different views of the safety shield;

FIGS. 19 to 22 show different views of the longitudinal housing;

FIGS. 23 and 24 show perspective views of a syringe holder;

FIG. 25 shows the assembled prefilled syringe;

FIGS. 26 and 27 show an exploded perspective views of a rigid needleshield and an insert thereof;

FIG. 28 shows a perspective view of the syringe body;

FIG. 29 is a perspective view of the stopper;

FIGS. 30 to 33 are different views of the trigger element;

FIGS. 34 and 35 show different perspective views of the shield retentionindicator;

FIGS. 36 and 37 are perspective views of a plunger;

FIG. 38 is a perspective view of the shield retention indicator inner;

FIGS. 39 to 41 are different views of the retainer;

FIGS. 42 and 43 are different perspective views of the a distal end cap;

FIGS. 44a to 44d is a side view (FIG. 44a ) and different longitudinalsectional views of the device according to the invention in an initialstate, wherein FIG. 44b is a longitudinal sectional view rotated by 90°relative to FIG. 44a , FIG. 44c is a longitudinal sectional view rotatedby 180° relative to FIG. 44a , and FIG. 44d is a longitudinal sectionalview rotated by 45° relative to FIG. 44 a;

FIGS. 45a to 45d are views according to FIGS. 44a to 44d in a conditionin which the removable cap is partially twisted-off from thelongitudinal housing;

FIGS. 46a to 46d are views according to FIGS. 44a to 44d in a conditionin which the removable cap is entirely removed from the longitudinalhousing and the device is ready for dispensing the fluid product;

FIGS. 47a to 47d are views according to FIGS. 44a to 44d in a conditionin which the device already pressed against a patient's skin, whereinthe safety shield is partially pressed into the longitudinal housing;

FIGS. 48a to 48d are views according to FIGS. 44a to 44d in a conditionin which the device is pressed against a patient's skin, wherein theinjection needle is pierced into the patient's skin, the safety shieldis fully depressed into the longitudinal housing and dispensing of thefluid product is initiated;

FIGS. 49a to 49d are views according to FIGS. 44a to 44d in a conditionin which the fluid product is being partially dispensed;

FIGS. 50a to 50d are views according to FIGS. 44a to 44d in a conditionin which the fluid product is being nearly entirely dispensed, whereinindicating mechanism is triggered;

FIGS. 51a to 51d are views according to FIGS. 44a to 44d in a conditionin which the fluid indicator reaches its final position;

FIGS. 52a to 52d are views according to FIGS. 44a to 44d in a conditionin which the fluid product is fully dispensed;

FIGS. 53a to 53d are views according to FIGS. 44a to 44d in a conditionin which the device is in the process of being removed from theinjection site on the patient's skin, wherein the needle is partiallyretracted out of the patient's tissue and the safety shield is partiallyreleased;

FIGS. 54a to 54d are views according to FIGS. 44a to 44d in a conditionin which the device is in the process of being removed from theinjection site on the patient's skin, wherein the needle is entirelyretracted out of the patient's tissue and the safety shield is furtherreleased;

FIGS. 55a to 55d are views according to FIGS. 44a to 44d in a conditionin which the device is entirely removed from the injection site on thepatient's skin, wherein the needle is entirely retracted out of thepatient's tissue and the safety shield is fully released;

FIGS. 56a to 56d are views according to FIGS. 44a to 44d in a conditionin which the device is entirely removed from the injection site on thepatient's skin, wherein the safety shield is blocked against a furtheraxial depression;

FIGS. 57 to 60 are different views of further examples of syringeholders;

FIG. 61 is a perspective view of a different drug delivery device in anassembled state;

FIG. 62 is an exploded view of the drug delivery device according toFIG. 1 showing subassemblies thereof;

FIG. 63 is an exploded view showing the components of a syringe unitsubassembly including a front cap according to FIG. 62;

FIG. 64 is an exploded view showing the components of a syringesubassembly according to FIG. 62;

FIG. 65 is an exploded view showing the components of a power packsubassembly according to FIG. 62;

FIGS. 66a and 66b are different perspective views of a distal end capbody;

FIG. 67 is a perspective view of a distal end cap cover;

FIG. 68 is a perspective view of a blade washer;

FIGS. 69a and 69b are perspective views of a safety shield of thesyringe unit subassembly;

FIG. 70 is a perspective view of a safety shield indicator;

FIGS. 71a and 71b are perspective views of a lock ring of the syringeunit subassembly;

FIGS. 72a and 72b are perspective views of a syringe holder of thesyringe unit subassembly;

FIGS. 73a and 73b are perspective views of a housing of the syringe unitsubassembly;

FIG. 73c is a side view of the housing of the syringe unit subassemblyfrom the right showing the inner structure;

FIG. 74 is a perspective side view of a rigid needle shield;

FIG. 75 is a perspective side view of a needle receiving insert for therigid needle shield;

FIG. 76 is a perspective view of a glass body including a needle;

FIG. 17 is a perspective view of a stopper;

FIGS. 78a and 78b are different perspective views of a plunger rod ofthe power-pack subassembly;

FIGS. 79a and 79b are perspective views of a shield retention trigger ofthe power-pack subassembly;

FIGS. 80a and 80b are perspective views of a shield retention indicatorof the power-pack subassembly;

FIGS. 81a and 81b are perspective views of a retainer of the power-packsubassembly;

FIGS. 82a and 82b are perspective views of a rotary click element of thepower-pack subassembly;

FIGS. 83a and 83b are perspective views of a snap-fit distal end cap ofthe power-pack subassembly;

FIGS. 84a and 84b show a drug delivery device in a ready to use state,wherein FIG. 84a shows a side view and FIG. 84b shows a longitudinalsectional view;

FIGS. 85a and 85b are longitudinal sectional views of the drug deliverydevice in a state where the end cap has just been removed, wherein FIG.85a is the longitudinal section along plane A indicated in FIG. 61 andwherein FIG. 85b is the longitudinal section along plane B indicated inFIG. 61;

FIGS. 86a and 86b are longitudinal sectional views according to FIGS.85a and 85b in a state, when the drug delivery device is fully pressedagainst the patient's skin and the drug delivery is just started;

FIGS. 87a and 87b are longitudinal sectional views according to FIGS.85a and 85b in an intermediate state, when the drug delivery devicedelivers the drug to the patient;

FIGS. 88a and 88b are longitudinal sectional views according to FIGS.85a and 85b in an intermediate state, when the drug delivery is close toan end;

FIGS. 89a and 89b are longitudinal sectional views according to FIGS.85a and 85b in a state, when the drug delivery device has fullydelivered the drug to the patient;

FIGS. 90a and 90c are longitudinal sectional views according to FIGS.85a and 85b in a state, when the drug delivery device is removed fromthe patient's skin and secured in a locked state after use; and

FIG. 90c is a perspective view of the drug delivery device in the lockedstate after use.

FIG. 1 a shows an automatic mechanical drug delivery device 10, formedas an auto-injector, according to the invention in a perspective sideview. The device 10 comprises a longitudinal body 12 extending along anaxis X and a removable end cap 50 at the proximal end of the device 10.The end of the device 10 to which the removable end cap 50 is located iscalled within this description the proximal end, which will be incontact with the patient. The opposite end, in FIG. 1 on the right sideis called the distal end within this description.

FIG. 1 furthermore schematically shows two different view directions A,B, C and D representing views (top view A) and planes of longitudinalsections B, C and D. In the following, when describing the structure andthe operation of the device 10, it is referred to these particular viewsA and planes of longitudinal sections B, C, D.

FIGS. 2, 3 and 4 show subassemblies 100, 200 and 300 of the device 10.In FIG. 2, one can see the proximal subassembly 100 including the endcap 50. In FIG. 3, one can see a subassembly including a prefilledsyringe unit 200. In FIG. 4, one can see a power-pack subassembly 300.These three subassemblies 100, 200 and 300 are provided as separatepre-assembled modules when assembling the device 10 according to theinvention. This allows to pre-assemble the syringe unit 200 and thepower-pack 300 and to provide a corresponding prefilled syringe 204 witha demanded medicament provided therein in a sealed manner and with thepredetermined volume for drug delivery.

As will be seen in the following, the three subassemblies 100, 200 and300 can be assembled to the device 10 by plugging the prefilled syringe200 into the receiving syringe unit 100 and thereafter plugging thepower-pack 300 from the right side, i.e. distal side, into the opendistal end of the body 12 of the syringe unit 100 until it locks into apredetermined non-separable position. By this modular structure, thedevice according to the invention can be easily assembled in anerror-free manner.

It is to be noted that although in the following a particular example ofthe device 10 is described in its structure and functioning in regard tothe figures, the components of the device 10 as described in thefollowing can be used also independently from the respective structure.In particular, each of the three subassemblies 100, 200 and 300 and thecomponents thereof can be used separately and independently from theother subassemblies. For example the proximal subassembly 100 and itscomponents can be used separately in another autoinjector, independentfrom the specific design of the syringe unit 200 or the power-pack 300.Therefore, the following description is not to be understood as alimiting disclosure in a way that each and every component can only beused together with the further components described in the followingcontext. Instead, the present disclosure is to be understood in a waythat each and every component disclosed therein can be claimed with itsrespective features separately independent from the interactingcomponents of the respective subassemblies.

In the following the components of the subassemblies are described indetail.

FIG. 2 shows an exploded view of the proximal subassembly 100. Thisproximal subassembly 100 comprises the removable end cap 50 formed by anend cap body 52, a blade washer 54 and a proximal end cap cover 56.Moreover, the proximal subassembly 100 comprises a safety shield 102, alongitudinal housing 104 and a syringe holder 106. These components willbe described in detail in regard to FIGS. 4 to 24 in the following.

FIG. 3 shows an exploded view of the components of the subassemblyforming the prefilled syringe 200. This syringe subassembly 200 includesa rigid needle shield 202 with an insert 207, a glass body 204 with anintegrally provided needle 206, a medicament 208 shown as a liquidcolumn and a stopper 210. These components of the prefilled syringe 200will be described in detail in regard to FIGS. 25 to 29.

FIG. 4 shows an exploded view of the components of the subassemblyforming the power-pack 300. This power-pack subassembly 300 includes atrigger element 302, a trigger spring 304, a shield retention indicator306, a plunger 308, a drive spring 310, a retainer 312, a shieldretention indicator inner element 314 and a distal end cap 316. Thesecomponents will be described in detail in regard to FIGS. 30 to 43 inthe following.

FIGS. 5 to 7 show the removable end cap body 52 from differentperspective views. One can see the cylindrical body 58 integrally formedwith an arch-like extension 60 such that the cylindrical body 58 forms anon-circular circumference providing an anti-roll shape when the end capis placed on a flat or slightly inclined surface. The outercircumferential surface of the body 58 has a number of integrally formedradial gripping recesses 62 extending in a longitudinal directionbetween the proximal and distal ends of the body 58. The proximal partof the body 58 is formed by a smooth outer surface 64. This surfaceincludes arrow-shaped surface offsets 66 which indicate the direction ofmovement for twisting-on or twisting-off the end cap 50 relative to thelongitudinal housing 12.

In its interior, the end cap body 52 includes a circular cylindricalsurface 68 forming an axially open receiving portion 70 with a smoothreceiving surface. Next to the receiving portion 70 there is anintegrally formed ring 72 portion. The ring portion 72 includes asubstantially flat cylindrical upper front surface 74 faced in distaldirection. Between the ring portion 72 and the inner circumferentialsurface 68 of the end cap body 52, there is an open gap 75 and aconnecting structure 76 connecting both components. The ring portion 72provides on its outer circumferential surface two projections 78extending in radial outward direction into the gap 74. On both sides ofthe projections 78, the outer circumferential surface of the ringportion 72 is provided with inclined lifting formations 80 and 82 whichhave the most distal level close to the projections 78 and which areinclined in distal direction to meet on an apex 84.

As one can see in FIG. 6 right below each projection 78, the outercircumferential surface of the ring portion 72 has two chamferedprojections 86 and 88, which form a receiving space 90 there between.This receiving space 90 is provided to receive and secure a projection198 formed on the inner circumferential surface the longitudinal housing104 on its proximal end, as will be described in regard to FIGS. 19 and20.

On its radial inner surface, the ring body 72 includes two oppositeprojections 92, protruding radial inwards. These two projections 92 areprovided for interacting with and securing corresponding radial outwardprojections 156 formed on the outer circumferential surface of theproximal end of the safety shield 102, as will be described in regard toFIGS. 14 to 18.

Focusing on FIG. 6, one can see that the end cap body 52 close to itsproximal end is faced with two annular arches 94 arranged in oppositerelation and fixed to the inner circumferential surface 68 of the endcap body 52 by means of a connection portion 96 and connecting ribs 98.

FIGS. 8 and 9 show the end cap cover 56. The end cap cover 56 has aproximal end cap portion 110 having the same basic surface with aslightly inclined projection 112 as the end cap body 52. An annularcylindrical body 114 extends from the proximal surface of the end capportion 110. The annular cylindrical body 114 is provided on its outercircumferential surface 116 with a plurality of longitudinal ribs 118which protrude over the distal end of the annular cylindrical body 114.At the free end of these longitudinal ribs 118, snap fit projectionsprotruding radially outwardly can be provided, as far as necessary,which engage into a corresponding (annular) recess within the end capbody 52. In its interior the annular cylindrical body 114 is providedwith chamfered radially extending ribs 120 running into an innercylindrical body 122, which is also integrally formed with the distalsurface of the end cap portion 110. The distal front surface of thearrangement formed by the cylindrical body 114, the projections of theribs 118, the radially inner ribs 120 and the inner cylindrical body 122form a conical profile.

FIGS. 10 to 13 show two different examples of the blade washer 54. Theblade washer 54 has a circular outer circumference 130 surrounding aring-shaped body 132. The blade washer 54 includes four radiallyinwardly extending lobes 134 integrally formed with the ring-shaped body132 and ending in a circular radially inner gripping surface 136. In aside view, one can see that the blade washer 54 according to the exampleshown in FIGS. 10 and 11 is flat, whereas the blade washer 54 accordingto the example shown in FIGS. 12 and 13 has a frustoconical shape. Inboth examples the lobes 84 provide an axial spring action, i.e. thelobes 84 can be deflected elastically in axial direction.

In an assembled state of the end cap 50, the blade washer 54 is arrangedon the proximal surface of the annular arches 94. The end cap cover 56is pressed into the proximal end of the end cap body 52, whereby theprotruding ends of the ribs 118 engage the ring-shaped body 132 of theblade washer 54 and presses it (as an optional feature) against theannular arches 94. The blade washer 54 is thereby fixedly held andbiased, or it is arranged alternatively with some axial clearance,between the proximal front surface of the annular arches 94 and theconical structure formed on the distal side of the end cap cover 56. Theconical structure formed on the distal side of the end cap cover 56provides sufficient distance to the lobes 84 such that the lobes canflex proximally in axial direction within this assembly.

As an optional feature, one or two lobes 134 can have a different lengththan the other lobes 134 such that when engaging the rigid needle shield202, there is asymmetric force load-balancing on the rigid needle shield202. This leads to a tilting or turning action such that the rigidneedle shield 202 is deflected from its original position. Thereby,recapping, i.e. re-plugging the cap 50 onto the housing once it has beenremoved, can be avoided.

FIGS. 14 to 18 show the safety shield 102 in different perspectiveviews. The safety shield 102 includes a ring-shaped hollow cylindricalbody 150 at its proximal end with two diametrically opposinglongitudinal arms 152, 154. This arrangement of the body 150 and thelongitudinal arms 152, 154 can be integrally formed or formed fromseparate pieces, i.e. the cylindrical body may include a separate coverwhich can be formed from a coloured material.

The ring-shaped body 150 has two projections 156 close to its distalend. The distal end of the ring-shaped body 150 is provided with anannular collar 158 having a rounded outer circumferential ring 160 withtwo opposite slots 162. A longitudinal hollow portion 164 extends fromthis annular collar 158 in distal direction, divided by the slots 162 intwo separate halves. The two longitudinal arms 152, 154 are integrallyformed with the distal end of the collar 158 and have a stepped course,such that a first transition 166 between the collar 158 and a firstlongitudinal arm portion 168 forms a first shoulder and wherein a secondtransition 170 between the first longitudinal arm portion 168 and asecond longitudinal arm portion 172 forms a second inclined shoulder.Each of the second longitudinal arm portions 172 has on its outercircumferential surface a projection 174 protruding radially outwardsand having a sharp radial surface facing in proximal direction and aninclined chamfered surface facing in distal direction. In line with theprojection 174 the longitudinal arm portion 172 has a rectangle athrough hole 176 close to its distal end.

The inner circumferential surface at the distal end of each secondlongitudinal arm portion 172 includes an inner guiding profile 178.Moreover, the inner circumferential surface of the cylindrical body 150includes four guiding ribs 180 protruding radially inwards. These innerguiding ribs 180 are provided for guiding the rigid needle shield 202.

The cylindrical body 150 is smoothly formed and radiused on its front(proximal) end such that it does not injure or scrape on the patient'sskin. As mentioned above, the cylindrical body 150 together with thelongitudinal arms 152, 154 can be a single-piece arrangement or amulti-piece assembly.

FIGS. 19 to 22 show the housing 104 in different views. The housing 104has the purpose of forming the main body 12 of the device 10. It isformed from a stable, rigid, transparent or opaque material. If notentirely transparent, the housing can be formed with drug viewingcutouts or transparent windows in order to make the drug, and the stateof the device visible to a user. The housing 104 is formed by alongitudinal tubular member 190. At its proximal end, the tubular member190 is provided with a hollow cylindrical portion 192 having a circularcross-section and a front surface 194. In a distance from the proximalend, the longitudinal member 190 is provided with a rounded hollowextension 196 having the same shape and cross-section as the extension60 of the removable cap, in order to provide a geometry with ananti-roll function on a flat surface. At the proximal end, thecylindrical portion 192 is provided on its circumferential inner surfacewith two rib-like opposing projections 198, protruding radially inwards,which are thereby hidden to the outside and which are adapted tointeract with the removable and cap 50. Moreover, in its middle section,the housing 104 is provided with two opposing longitudinal through holes220, having the function of guiding slots. As an alternative, thesethrough holes 220 can be replaced by guiding channels which open to theinside of the housing 104, but which are closed on the outercircumferential surface thereof. In line with the guiding slots 220 butcloser to the distal end, the housing is provided with two furtheropposing through holes 222, which as an alternative can be also providedas internal recesses which are closed at the outer circumferentialsurface. Close to its distal end, the housing 104 is provided with apair of opposing transverse through holes 224, which as an alternativecan be also provided as internal recesses which are closed at the outercircumferential surface. The distal end is further provided with adistal front surface 226, which has two opposing short notches 228.

In its interior, the housing 104 is provided with a double-ringstructure 230, which is integrally connected to the tubular member 190in the region of the cylindrical portion 192 by means of pair ofopposing rigid connecting arms 232. The connecting arms 232 are formedby a stable U-shaped structure with two lateral longitudinal connectingribs 234 and one transverse connecting rib 236 running incircumferential direction. The size of the connecting ribs and theU-shaped sectional shape are to provide structural rigidity to thehousing 104. This joining geometry is also important for the flow of thematerial when the component is molded.

Moreover, the double-ring structure 230 has an outer ring 238 runningwith a conical transition portion 240 into a hollow inner ring 242. Tothe proximal end, two strengthening ribs 244 stabilize the connectionbetween the outer ring 238 and the inner ring 242. Faced to the distalend, the conical transition portion 240 is provided with two opposingcutouts 246 and one rib-like axial projection 248. The arrangement ofthe two opposing cutouts 246 and the axial projection 248 are providedfor positioning the prefilled syringe 200 in connection with the syringeholder 106. For some variants projection 248 may or may not be included.

FIGS. 23 and 24 show one example for the syringe holder 106. Otherexamples of the syringe holder are described in regard to FIGS. 57 to60.

The syringe holder 106 has the purpose to receive and hold the prefilledsyringe 204 within the housing 104. It is adapted to receive differentkinds of syringes with different volumes of medicament without the needof changing the dimensions of other components of the device 10.Therefore, different sizes for syringe holders 106 are to be provided inadaptation to the different kinds/volumes of syringes.

The syringe holder 106 provides a longitudinal body 260. At its proximalend, the syringe holder 106 is formed with a rigid and non-elasticU-shaped element 262, which is open in one radial direction, as can beseen in FIG. 23. This rigid U-shaped element 262 at the proximal end isreinforced by two parallel surrounding ribs 264, 266. At the proximalfront surface, the U-shaped element 262 is provided with two transverseribs or projections 268. At its distal end, the syringe holder 106 isprovided with a rigid and non-elastic similar U-shaped element 270,reinforced with two parallel surrounding ribs 272, 274. The twosurrounding ribs 272, 274 are provided with cutouts 276, 278, facingradially outwards on opposite positions. The two rigid U-shaped elements262 and 272 are connected by two longitudinal and rigid connecting arms280, 282. Each of the connecting arms extends in a straight manner andincludes in its middle section in FIG. 23 on the upper end a projection284, 286 projecting radially inwards such that they are faced to oneanother. The inner surface 288 of the projections 284, 286 is rounded,as can be seen in FIGS. 23 and 24, such that a glass body of the syringe200 can be arranged and held therein.

When placed within the longitudinal housing 104, the syringe holder 106holding a prefilled syringe 200, preferably in the rotational manner, ispositioned such that the two projections 268 engage into the cutouts 246of the double-ring structure 230 and the projection 248 engages into thehollow space provided by the proximal U-shaped element 262. Thereby, thesyringe holder 106 is positioned by the double-ring structure 230 withinthe longitudinal housing 104 in an appropriate axial and rotationalposition around the longitudinal axis.

FIG. 25 shows the prefilled syringe 200 in an assembled state, whereinthe rigid needle shield 202 is placed on the proximal front end of thesyringe covering the injection needle 206.

FIGS. 26 and 27 show perspective views of the rigid needle shield 202with the insert 207. The rigid needle shield 202 is formed by a tubularmember 320 with an open distal end 322 and a closed proximal end 324. Inits front portion it has a surface formed with transverse gripping ribs326. Close to its distal end, it has two opposite rectangular throughholes 328.

The insert 207 is formed by a soft deformable material and can bepressed into the rigid needle shield 202 such that it is fixedly heldtherein. It has an annular collar 330 close to its distal end whichengages with the rectangular through holes 328 of the rigid needleshield 202.

FIG. 28 shows the syringe 204. The syringe 204 is formed by a hollowcylindrical glass body 332 having an open distal end 334, which issurrounded by a circumferential annular collar 336 with two flattenedopposite side surfaces 338. At its proximal portion, the cylindricalglass body 332 is formed with a rounded taper 340 and transits into ahollow conical glass portion 342 ending in a stepped needle hub 344 witha spherical or rounded proximal head 346. The proximal head 346 fixedlyholds said injection needle 206 with a sharpened needle tip 348.

FIG. 29 shows the stopper element 210 formed from a flexible material,e.g. a rubber. At its proximal portion, it has a smooth cylindricalouter circumferential surface 350, which has a diameter adapted to theinner diameter of the hollow cylindrical glass body 332 of the syringe204 such that the stopper element 210 slidably engages the innercircumferential surface of the hollow cylindrical glass body 332 in afluid tight manner. On the distal portion of the outer surface, thestopper element 210 is provided with four circumferential annularrecesses forming three circumferential sealing ribs 352. The stopperelement 210 has cup-shape with a closed proximal end 354 and an opendistal end 356.

Turning now to the components of the power-pack or drive assembly, FIGS.30 to 33 show the trigger element 302 in different views. The triggerelement is formed by a tube -shaped hollow body 360. At its proximal endit has a front surface 362 surrounded by a chamfered rim 363 andprovided with two opposite lateral tabs 364, 366 extending in radialdirection. From the front surface 362 of these lateral tabs 364, 366 tworectangular projection plates 368, 370 extend in longitudinal axialdirection. The projection plates 368, 370 are provided with chamferedprojections 372, extending radially outwardly. The tube shaped hollowbody 360 extends in distal direction and provides in its middle portiona surrounding annular reinforcement rib 374 connected to the reinforcedproximal end by longitudinal ribs 376. Moreover, between the proximalend 362 and the reinforcement rib 374, two opposing rectangular hollowbox elements 378 or recesses formed by other wall structures areprovided at the outer circumferential surface of the trigger element302, wherein these box elements 378 or recesses provide a hollow space379, respectively, in which additional components, e.g. electronicsensors or the like can be provided.

Further in distal direction, the outer circumferential surface of thetubular hollow body 360 is provided with a further annular andcircumferential reinforcement rib 380, having an L-shaped profile tosupport the spring 304. The distal end of the tubular hollow body 360 ofthe trigger element 302 is formed by a hollow cylindrical portion 382having a front surface 384. In its interior, the trigger element 302 isprovided with four longitudinal guiding ribs 386, wherein two pairs ofthese guiding ribs 386 are connected by an arch-like connecting rib 388,respectively, which extends in circumferential direction along the innercircumferential surface of the tubular hollow body 360.

FIGS. 34 and 35 show the shield retention indicator 306. The shieldretention indicator 306 is formed by a hollow cylindrical body 400having an annular cylindrical component 402, which is extended by arounded extension 404 adapted to the geometry of the housing 104. It isreceivable in a slidable but form-fitting manner within the extendedportion 196 of the hollow cylindrical body 190 of the longitudinalhousing 190. It has a smooth outer circumferential surface 406. At itsproximal end, the shield retention indicator 306 is provided with fourlongitudinal flexible arms 408, each having a proximal free end 410. Thefree ends 410 of the flexible arms 408 are provided with protrusions 412extending radially inwardly and reinforced by short longitudinalchamfered ribs 414. The distal end of the shield retention indicator 306is provided with a circular opening 416.

The circumferential outer surface 406 of the shield retention indicator306 has a signalling colour, i.e. yellow, orange or red, or a signallingpattern which is clearly visible by a user. Thereby, as will bediscussed in detail in regard to the operation of the drug deliverydevice 10 according to the present invention, the user, i.e. the medicalpractitioner or the patient, of the device 10 can easily recognize whenthe shield retention indicator 306 is moved into a signalling positionin which it is clearly visible through the longitudinal housing 104 fromthe outside.

FIGS. 36 and 37 depict the plunger 308 in different perspective views.The plunger 308 is formed by a longitudinal pipe-shaped hollow element420 which has at its proximal end a plunger head 422. The plunger head422 is provided with a front surface 424 and a transverse slot 426. Thefront surface 424 includes a small cylindrical through hole 428. Thefront surface with the transverse slot 426 and the cylindrical throughhole 428 can be coupled with an additional plunger head element, ifneeded e.g. for syringes having a larger inner diameter interacting witha correspondingly large stopper 210. This additional enlarged plungerhead can be used for larger syringes, e.g. having a drug volume of 2.25ml. In case of smaller syringes, as shown in the example, e.g. syringeshaving a drug volume of 1 ml, the enlarged plunger head is omitted andthe plunger 308 has just straight cylindrical shape on its proximal end.

In the middle portion of the plunger 308, a pair of opposing rectangularthrough holes 430 is provided in the wall of the hollow element 420.According to another example, the plunger may have additional pairs ofthrough holes, comparable to the through holes 430, which allow anadaptation to different syringe sizes or filling volumes of the drug. Atthe distal end, the hollow element 420 is provided with a circularopening 432 providing access in longitudinal direction for receiving thedrive spring 310.

FIG. 38 shows the shield retention indicator inner element 314. Thiselement is formed by a stepped tubular body 440 having a first hollowcylindrical portion 442 with a smaller diameter and an enlarged secondhollow cylindrical portion 444 with a larger diameter. At its proximalend, the shield retention indicator inner element 314 is provided withtwo opposing flexible longitudinal arms 446 extending in proximaldirection, wherein a first portion 448 runs in longitudinal direction, asecond portion 450 is slightly inclined radially inwards, and a thirdportion 452 extends in longitudinal direction, however, on a radiallevel which is further radially inwards than the first portion 448. Atits proximal end, each of the arms 446 has an inclined retainingprojection 454 extending radially outwards.

The distal portion of the shield retention indicator inner element 314is provided with an end plate 456 having the same rounded and extendedcross-sectional surface as the distal end of the shield retentionindicator 306. The diameter of the outer circumferential surface of thesecond hollow cylindrical portion 444 is adapted to be received withinthe circular opening 416 provided in the distal end of the shieldretention indicator 306.

FIGS. 39 to 41 depict the retainer 312 of the power-pack 300 or driveassembly. The retainer 312 acts as the control member including aplurality of control functions of the power-pack 300. The retainer 312is formed from a hollow cylindrical body 470. On two opposing sides thecylindrical body 470 includes a U-shaped cutout 472 forming alongitudinal flexible arm 474, respectively. The longitudinal flexiblearm 474 is integrally connected to the hollow cylindrical body 470 atits distal end 476. At its proximal end, the flexible arm 474 isprovided with a chamfered radial outward projection 478 and, on theopposite side, i.e. on its radial inner side, with a correspondingchamfered radial inward projection 480. Moreover, the cylindrical body470 is provided with two opposing longitudinal cutouts 482 in an arearotated by 90° relative to the flexible arms 474 formed by the cutouts472. The longitudinal cutouts 482 extend approximately with the samelongitudinal extension as the U-shaped cutout 472, however slightlyfarther in distal direction. In the region of about one third of thelongitudinal length of the cutouts 482 close to their proximal end, thecylindrical body 470 comprises lateral projections 484 transverselybridging the cutouts 482. These lateral bridging projections 484 arecontinued close to the proximal end by additional projections 486 havingthe same outer circumferential shape.

At its proximal end, the cylindrical body 470 is provided with twoflexible arms 490 integrally formed with the cylindrical body 470 andinclined by an angle of about 45° relative to the proximal front surfaceof the hollow cylindrical body 470. These flexible arms 490 areconnected to a ring-shaped head portion 492. The ring-shaped headportion 492 is formed as a bushing with a cylindrical portion 494 andtwo opposing proximal arch-like projections 496. The head portion 492can be integrally formed with the flexible arms 490 or formed as aseparate piece fixedly connected to the flexible arms 490, e.g. by meansof an intermediate connecting ring.

At its distal end, the cylindrical body 470 is formed with acircumferential groove 500. The distal end is provided with a distal endsurface 502 having a central opening 504. In its interior close to thedistal end, the cylindrical body 470 is provided with inner guiding ribs498 running in axial or longitudinal direction between the distal endsurface 502 and the longitudinal section having the circumferentialgroove 500.

FIGS. 42 and 43 depict the distal end cap 316 of the device 10. Thedistal end cap 316 has a distal end cap body 510 having the samecross-sectional profile as the distal end of the longitudinal housing104, i.e. rounded with an extension. The distal end cap body 510 isformed from a transparent material and closed by a distal surface 512. Atransition 516 between the circumferential surface 514 and the distalsurface 512 is rounded or chamfered. At its proximal end, the distal endcap 316 is provided with a plug-in portion 520, which is form-fittinglyreceived in an assembled state within the distal end of the longitudinalhousing 104. Therefore, the plug-in portion 520 has a reduced outerdiameter and transits to the distal end cap body 510 via a step surface522.

In the region of the step surface 522 the distal end cap 316 provideslongitudinal protrusions 524 corresponding to the notches 228 describedin regard to FIGS. 19 to 22 for the longitudinal housing 104. Byinteraction of the protrusions 524 and the notches 228, the distal endcap 316 is positioned relative to the longitudinal housing 104.Moreover, the plug-in portion 520 provides two longitudinal projections526 on the proximal end. The outer circumferential surface of theselongitudinal projections 526 is formed with chamfered snap-fitprojections 528, respectively. These projections 528 are provided toengage in a snap-fit manner with the corresponding through holes 224provided in the longitudinal housing 104 when assembling the device.

It is to be mentioned that the snap-fit engagement between theprojections 528 and the through holes 224—once assembled—is notseparable. The device according to the present invention is a single usedevice and excludes that the distal end cap 316, after having been fixedto the longitudinal housing 104, is removed from the housing 104 again.It is not provided or intended to replace or refill the syringe 200after use or to provide any other access to the interior and thecomponents of the device 10, once it has been used.

Turning to the interior of the distal end cap 316, one can see in FIG.43 that the end cap is provided with a hollow cylindrical body 530integrally formed with a bottom surface 532 of the distal end cap 316.

In the following, the assembled state of the device 10 is described inregard to FIGS. 44a and 44d . FIGS. 44a shows a side view and FIGS. 44bto 44d show different longitudinal sectional views of the deviceaccording to the invention in an initial state, wherein FIG. 44b is alongitudinal sectional view rotated by 90° relative to FIG. 44a , FIG.44c is a longitudinal sectional view rotated by 180° relative to FIG.44a , and FIG. 44d is a longitudinal sectional view rotated by 45°relative to FIG. 44a . Reference is made to the planes and arrows A, B,C, D depicted in FIG. 1. The shown state is also the initial state ofthe device 10, i.e. the state of the device how it is delivered to theuser.

In the assembled or initial state of the device 10, the end cap 50 isscrewed onto the longitudinal housing 104, wherein the end cap 50 isheld in circumferential direction by an engagement of each of the innerprotrusions 198 formed on the proximal end of the housing 104 within acorresponding receiving space 90 between the two projections 86 and 88formed inside the end cap body 52. Moreover, the end cap 50 is held inlongitudinal direction by an engagement of each of the inner protrusions198 formed in the proximal end of the housing 104 located behind theprojections 78 formed on the inner ring portion 72 of the end cap body52, respectively. Thereby, the removable cap 50 is held on the housingagainst an axial withdrawing force by the projections 78 as well asagainst small twist-off forces, which are below a twist-off forcethreshold value, by the opposing projections 86 and 88 forming thereceiving space 90.

Moreover, the safety shield 102 is held in the assembled initial stateaccording to FIGS. 44a to 44d by the removable cap 50 in the axialposition shown in FIGS. 44b to 44d . In particular this has the purposeto avoid unintended movement in distal direction, i.e. if the device 10is dropped and experiences a shock when it falls on the ground. This isachieved by an engagement between the projections 156 formed on theouter circumferential surface of the cylindrical body 150 at theproximal end of the safety shield 102 and the two projections 92 formedon the inner circumferential surface of the inner ring portion 72 of theremovable cap body 52. Thereby, the projections 92 block any axialmovement of the safety shield 102 in distal direction relative to theremovable cap 50 mounted to the housing 104 and thereby relative to thehousing 104.

At the distal end, the distal end cap 316 is fixedly and inseparablyattached by the snap-fit arrangement to the longitudinal housing 104,wherein the projections 526 formed on the outer circumferential surfaceof the plug-in portion 520 of the distal end cap 316 engage into thethrough holes 224 formed on the distal end of the housing 104.

Moreover, in the assembled state, the syringe 204 is held within thesyringe holder 106, which is received in the ring structure 230 of thehousing 104. As described above, the syringe holder is positionedrelative to the housing 104 by means of the ring structure 230, whereinthe transverse projections 268 engage into the respective cutouts 246and the projection 248 projects into the hollow space provided by theU-shaped element 262 of the syringe holder (see above). The syringe 204is pressed in axial direction into the syringe holder 106. The U-shapedelements 262 and 272 are rigid and do not flex-out during assembly orduring operation. It is to be noted that the syringe 204 is heldrotationally within the syringe holder 106.

Moreover, the syringe 204 together with the syringe holder 106 arepressed via the syringe flange 336 by means of the head portion 494 ofthe retainer 312 in proximal direction against the conical and steppedring structure 230 of the housing 104, wherein the flexible arms 490 ofthe retainer act as axial spring means providing a spring force in axialproximal direction in order to hold the syringe 204 in place within thesyringe holder 106 and positioned thereby. The rigid needle shield 202engages the hollow conical glass portion 344 by means of the insert 207.The soft insert 207 safely covers the needle 206 and maintains sterilityof the injection needle 206 and the medicament contained within thesyringe 204 and the needle 206. As one can see in FIG. 44b , the outersurface of the tubular member 320 with the transverse gripping ribs 326or as an alternative just with a soft outer surface is engaged by theflexible lobes 134 of the blade washer 54 which has a conical shape inthis example. As mentioned above, the flexible lobes 134 can havedifferent radial lengths to provide an unbalanced force onto the rigidneedle shield 202. The blade washer 54 is held within the removable endcap 50 by means of the cap cover 56.

Moreover, FIGS. 44b to 44d show the ring-shaped cylindrical body 150 ofthe safety shield 102. The safety shield 102 is pressed by the end cap50 via the longitudinal arms 152, 154 against the force of the shieldspring 308 in distal direction partially into the housing 104. Thetrigger element 302 acts as an intermediate element between thelongitudinal arms 152, 154 and the shield spring 304. As one can see inFIG. 44c , the trigger element 302 is in the assembled state permanentlycoupled via its projection plates 368, 370 with the distal ends of thearms 152, 154 of the safety shield 102. The projection plates 368, 370are received within the inner guiding profile 178 at the distal end ofthe arms 152, 154. Moreover, the chamfered projections 372 engage intothe through holes 176, respectively, and thereby prevent in theassembled state that the arms 152, 154 of the safety shield 102 areseparated under an axial force from the projection plates 368, 370 ofthe trigger element 302. The chambers of the projections 372 and aguiding profile 178 of the distal end of the arms 152, 154 facilitatethe assembling process.

The proximal end of the shield spring 304 engages against the distalportion 382 of the trigger element 302 and abuts against thecircumferential rib 380 of the trigger element 302, whereincircumferential rib 380 having an L-shaped profile holds tightly theproximal end of the shield spring 304. The distal end of the shieldspring 304 presses via the distal end of the shield retention indicator306 against the flanged proximal surface of the plate 456 of the shieldretention indicator inner element 314.

Furthermore, the shield retention indicator 306 with its cylindricalbody 406 receives and surrounds the shield retention indicator innerelement 314 as well as the shield spring 308. The four longitudinal arms408 of the shield retention indicator 306 extend in proximal directionthrough the gaps provided between the lateral tabs 364, 366 and the boxstructures 378, each of them projecting in radial outward direction fromthe trigger element 302. The four longitudinal arms 408 pass the triggerelement 302, such that the protrusions 412 of the arms 408 engage theouter circumferential surface of the retainer 314, as can be seen inFIGS. 44b and 44 c.

The retainer 312 is fixedly held within the distal end cap 316 by thehollow cylindrical body 530 gripping with an inner circumferentialprojection into the outer circumferential groove 500 of the retainer ina form-fitting manner. Thereby, the retainer 312 is fixed within thedevice 10 against any movement in axial direction as well as againsttilting.

The shield retention indicator 306 together with the shield retentionindicator inner element 314 are held in the axial position by means ofthe arms 446 in spite of the compressed shield spring 304 and theresulting axial drive forces. This is achieved due to the fact that thearms 446 reach through the longitudinal cutouts 482 of the retainer 312and engage with their radial retaining projections 454 behind thelateral projections 484 of the retainer 312 bridging the cutouts 382 ofthe retainer 312. Moreover, in this state, the outer circumferentialsurface of the plunger 308 arranged radially inside the arms 446prevents that the arms 446 flex radially inwards and escape from theholding function on the lateral projections 484.

The plunger 308 retains the main spring 310 in a compressed state, asdescribed in the following. The proximal end of the compressed mainspring 310 presses against the proximal end of the plunger 308. One cansee that the proximal end 422 of the plunger 308 is slidably receivedwithin the hollow glass body 332 of the syringe 204 close to the stopperelement 210. Moreover, one can see the medicament 208 as a liquid columnincluded within the syringe 204. The distal end of the main spring 310protrudes out of the plunger 308 and is received within the hollowinterior of the retainer 310 where it is supported against its distalend. The plunger 308 is held in its axial position against the driveforce of the main spring 310 due to engagement between the flexible arms474 with the radial inward projections 480, which engage into thethrough holes 430 provided in the plunger 308. As noted in thedescription above it is possible to provide additional through holes430, or slots, with which the projections 480 engage. The longitudinalposition of the projections 480 is fixed within the device and so thelongitudinal position of the through holes 430 determined the initialposition of the plunger within the device. As shown, the plunger head422 is reasonably close to the stopper 210, but with a smaller fillvolume the stopper 210 may be closer to the proximal end and so furtherfrom the plunger head 422. This could lead to an undesirably largeimpact between the plunger head 422 and the 210. In such casesadditional through holes 430 longitudinally offset from the originalthrough holes 430 could be included on the plunger 308 to offset theinitial position of the plunger 308. As the flexible arms 474 are keptin position by a contact between their radial outward projections 478and the inner circumferential surface of the trigger element 302, theflexible arms 474 cannot flex radially outwardly in reaction to thedrive force of the compressed main spring 310. Thereby, the plunger 308is held by the flexible arms and their radial inward projections 480 inplace.

From this fully assembled initial position, the device 10 according tothis example of the invention is used as follows:

Twisting of the Removable End Cap 50

FIGS. 45a to 45d show views according to FIGS. 44a to 44d in a conditionin which the removable cap is partially twisted-off from thelongitudinal housing. The removable end cap 50 has been slightly rotatedrelative to the housing 104. No axial movement has taken place. Therelative rotation was performed to such a degree that the engagementbetween the projections 198 formed inside the proximal end of thehousing 104 and the projections 86 and 88 formed on the inner ringportion 72 of the end cap body 52 is dissolved. In order to achievethis, a certain threshold value for the twist-off force must be providedto overcome the engagement between the projections 198 of the housing104 and the projections 86, 88 of the removable end cap 50. Moreover,the engagement between the projections 156 on the proximal end 150 ofthe safety shield 102 and the projections 92 on the end cap body 52 isalso dissolved during this relative movement. In this state, there is noaxial engagement between the removable end cap 50 and the housing 104.

Under further rotation between the removable end cap 50 and the housing104, the projections 198 are guided along the inclined surfaces of thelifting formations 80, 82. Moreover, during the further relativerotation between the removable end cap 50 and the housing 104 performedby a user by applying the twist-off force, the safety shield 102 ispressed out by the safety shield spring 304 in proximal axial direction.While the safety shield 102 with its proximal portion 150 is pressed outof the longitudinal housing 104, this force supports the removal of theremovable end cap 50 and also supports by using the mechanical benefitthe relative rotation between the removable end cap 50 and the housing104. Thus, by experiencing the force provided by the spring 304, theuser is guided to further rotate the end cap 50 relative to the housing104 and to separate the two components from one another.

The proximal portion 150 of the safety shield 102 moving out of thehousing 104 covers the needle. The relative movement between the safetyshield 102 and the housing 104 is guided by an interaction between theprojections 174 formed on each arm 152, 154 of the safety shield and thelongitudinal through holes 220, which act as longitudinal guidingchannels.

Moreover, during the removal of the end cap 50, the rigid needle shield202 which is gripped by the lobes 134 of the blade washer 54, iswithdrawn together with its insert 207 from the hollow conical glassportion 344 of the syringe 204. Due to the fact that the syringe 204 isrotationally supported within the syringe holder, unwanted coring can beavoided and the syringe is not harmed by the removal of the rigid needleshield 202. Finally the needle 206 with its needle tip 348 is exposedwithin the ring-shaped proximal body 150 of the safety shield 102.

Removable End Cap 50 Separated from the Housing 102

FIGS. 46a to 46d show views according to FIGS. 44a to 44d in a conditionin which the removable cap is entirely removed from the longitudinalhousing and the device is ready for dispensing the fluid product. Onecan see, that the removable end cap 50 is fully separated from thehousing 104. The proximal portion 150 of the safety shield 102 fullyprojects out of the housing 104 and covers the injection needle 206 withits needle tip 348.

Initiating Injection by Pressing the Device Against Patient's Skin

FIGS. 47a to 47d show views according to FIGS. 44a to 44d in a conditionin which the device 10 is already pressed against a patient's skin,wherein the safety shield is partially pressed into the longitudinalhousing 104.

As one can see, the proximal front surface of the proximal portion 150of the safety shield 102 is in contact with the patient's skin S. Thedevice 10 by holding the housing 104 is pressed against the patient'sskin S. Thereby, the safety shield 102 is pressed into the housing 104,resulting in a relative movement between these two components. Onceagain, the projections 174 formed on the arms 152, 154 of the safetyshield 102 and engaging into the longitudinal holes 220 of the housing104 guide the safety shield 102 along its relative linear movementrelative to the housing 104.

Due to the movement of the safety shield 102 into the housing 104, thearms 152, 154 press the trigger element 302 in distal direction.Thereby, the trigger element 302 is moved with its chamfered proximalrim 363 under the arms 408 of the shield retention indicator 306. As aconsequence, the arms 408 are flexed out, as shown in FIG. 47 d.

Starting Dispensing of the Drug by Further Pressing the Device AgainstPatient's Skin

When the device 10 is further being pressed against the patient's skinS, such that the safety shield 102 is further moved in distal directioninto the housing 104, the needle 206 is pierced into the patient's skinand finally the situation as shown in FIGS. 48a to 48d is reached. FIGS.48a to 48d show views according to FIGS. 44a to 44d in a condition inwhich the device is pressed against a patient's skin, wherein theinjection needle is pierced into the patient's skin, the safety shield102 is fully depressed into the longitudinal housing 104 and dispensingof the fluid product is initiated.

Due to the relative movement between the safety shield 102 and thehousing 104, the needle 206 is exposed and protrudes into the patient'sskin S. The safety shield 102 is pressed to such an extent into thehousing 104, that under compression of the spring 304, it has moved thetrigger element 302 with its front surface 362 beyond the projections478 of the flexible arms 474 of the retainer 314. Under the action ofthe main spring 310, the plunger 308 is pressed by the surroundingsurface of the through holes 430 in axial direction. The surroundingsurface of the through holes 430 engaging with the chamfer of the radialinner projections 480 of the flexible arms 474 presses under the forceof the main spring 310 the flexible arms 474 of the retainer 312 inradial outward direction. This is possible, as the retainer has movedbeyond the outer projections 478 of the flexible arms 474, as shown inFIG. 48c . As a result, the flexible arms 474 flex out and release theplunger 308 for axial movement in proximal direction.

Dispensing the Drug into the Patient's Tissue

FIGS. 49a to 49d show views according to FIGS. 44a to 44d in a conditionin which the fluid product is already partially dispensed. As theplunger 308 is no longer held in axial position by the flexible arms 374of the retainer 312, the plunger 308 moves in proximal direction,engages the stopper element 210 and presses the stopping element 210 inproximal direction under the action of the main spring 310. Thereby, thedrug is pressed out of the glass body 332 of the syringe 204 through theinjection needle 206 into the patient's tissue, as indicated by threethin arrows.

This process continues for a full dispensing of the drug into thepatient's tissue.

Reaching End of Dispensing Process and Triggering Indicating Mechanism

FIGS. 50a to 50d show views according to FIGS. 44a to 44d in a conditionin which the fluid product is being nearly entirely dispensed. In thisstage of the device, the indicating mechanism is being triggered. As onecan see, the stopper element 210 has nearly reached the proximal bottomsurface of the cylindrical glass body 332 of the syringe 204. Theplunger 308 has moved correspondingly far in proximal direction underthe expansion of the main spring 310. Thereby, the distal end of theplunger 308 has moved in proximal direction beyond the end of theflexible longitudinal arms 446 of the shield retention indicator innerelement 314. Thus, the outer circumferential surface of the plunger 308no longer blocks a radial inward flexing of the longitudinal arms 446.

Due to the compressed state of the spring 304, which is supported viathe trigger element 302 against the safety shield 104 and which tends toexpand in distal direction, the distal end of the spring 304 pressesagainst the distal end of the shield retention indicator 306 and pushesthe combined arrangement of the shield retention indicator 306 togetherwith the shield retention indicator inner element 314 in distaldirection. Thereby the longitudinal flexible arms 446 due to theinclined retaining projections 454 are flexed radially inwards and passthe lateral projections 484 bridging the cutouts 482. Thus, the combinedarrangement of the shield retention indicator 306 together with theshield retention indicator inner element 314 is free to move in distaldirection.

As outlined above, the outer circumferential surface 406 of the shieldretention indicator 306 has a signalling colour or pattern. As soon asit enters the transparent region of the distal end cap 316, which istransparent around the whole circumference, the user can see thesignalling colour or pattern.

Indicator Reaches Final Position

FIGS. 51a to 51d show views according to FIGS. 44a to 44d in a conditionin which the shield retention indicator 306 reaches its final position.One can see, that from the condition according to FIGS. 50a to 50d tothe condition according to FIGS. 51a to 51d the shield retentionindicator 306 is pressed entirely into the distal end cap 316 under theaction of the expanding spring 304.

When reaching the distal inner bottom surface of the end cap 316, theshield retention indicator inner element 314 hits with its endplate 456the inner bottom surface 532 of the distal end cap 316 and therebygenerates an audible and/or tactile signal. This hitting contactachieved under the action of the relaxing spring 304 acts in axialdirection and is clearly tangible by the user. Moreover, the soundgenerated thereby is loud enough to be heard by the user on the normalconditions as a clearly audible click signal. Thus, the user gets afeedback from the device 10 right after achieving the situation close tothe end of the fluid dispensing process.

It is to be mentioned, that the spring force of the spring 304 whenreleasing the combination of the combination of the shield retentionindicator 306 together with the shield retention indicator inner element314 in distal direction is strong enough to initiate this triggerfunction within a very short period of time, e.g. milliseconds or tenthsof a second.

Reaching the End of the Dispensing Process

As mentioned above, the signalling mechanism is triggered shortly beforethe end of the dispensing process has reached. This is due to the factthat the stopper element 210 has just not reached its end positionwithin the syringe glass body 332, as shown in FIG. 51a , when thesignalling mechanism is triggered.

FIGS. 52a to 52d show views according to FIGS. 44a to 44d in a conditionin which the fluid product is fully dispensed. In this situation, thestopper element 210 has reached the proximal end of the glass body 332of the syringe 204. As a consequence, the complete dose of the drug ispressed out of the syringe 204.

Starting Removing the Device 10 from the Patient's Skin

When the dose has been fully dispensed into the patient's tissue, thedevice 10 can be removed from the injection site. FIGS. 53a to 53d showviews according to FIGS. 44a to 44d in a condition in which the deviceis in the process of being removed from the injection site on thepatient's skin, wherein the needle is partially retracted out of thepatient's tissue and the safety shield is partially released.

One can see, that the housing 104 of the device 10 has been partiallywithdrawn from the patient's skin, wherein the proximal front portion150 of the safety shield 102 is still in contact with the patient's skinS. This is due to the fact that the still compressed spring 304 acts viathe trigger element 302 on the longitudinal arms 152, 154 of the safetyshield 102 and thereby presses under the action of the compressed spring304 the safety shield 102 out of the housing 104. Thereby, the injectionneedle 206, which is retracted together with the housing 104 out of thepatient's skin S is permanently covered during this retraction process.

This can be seen in FIGS. 53a to 53d . While retracting the housing 104,the safety shield 102 with its proximal end portion 150 remains incontact with the patient's skin S such that the needle is permanentlycovered.

Entirely Removing the Device 10 from the Patient's Skin

Finally, the housing 104 has been lifted so far from the patient's skin,that the needle is fully covered by the proximal end portion 150 of thesafety shield 102 and the proximal end portion 150 extends beyond thesharpened needle tip 348 of the injection needle. In other words, due tothe action of the expanding spring 304, the safety shield 102 is pressedto such an extent out of the housing 104, that it fully covers theneedle and protrudes over the needle tip 348.

FIGS. 54a to 54d show views according to FIGS. 44a to 44d in anintermediate condition in which the device is in the process of beingremoved from the injection site on the patient's skin, wherein theneedle is entirely retracted out of the patient's tissue and the safetyshield is further released.

FIGS. 55a to 55d show views according to FIGS. 44a to 44d in a conditionin which the device is entirely removed from the injection site on thepatient's skin, wherein the needle is entirely retracted out of thepatient's tissue and the safety shield is fully released. The axial endposition of the safety shield 102, i.e. its final position after beingpressed out of the housing 104 by the action of the expanding spring304, is determined by an abutment of the sharp proximal edges of theprojections 174 against the proximal end of the longitudinal throughholes 220. In this position, in spite of the spring force still appliedby the spring 304 in proximal direction, the safety shield 102 cannotmoved further in proximal direction. The proximal portion 150 of thesafety shield 102 has reached its position in which it protrudes out ofthe housing 104 at maximum. In this position, the sharpened needle tip348 is positioned well behind the proximal end of the portion 150 andsafety covered therein.

Blocking Distal Movement of Safety Shield 102 After Use

When pushing the safety shield 102 out of the housing 104, as describedabove, the combined arrangement formed by the shield retention indicator306 and the shield retention indicator inner element 314 is kept at thedistal end position within the distal end cap 316. However, as describedabove, due to the spring action of the spring 304, the trigger element302 is moved in proximal direction. Thus, the trigger element 302 ispressed under the spring force of the spring 304 out of the engagementof the arms 408 of the shield retention indicator 306. In other words,the arms 408 once again flex-out, as can be seen in FIGS. 52a to 52d twoovercome the proximal chamfered rim 363 of the trigger element 302.

During further movement of the trigger element 302 in proximaldirection, the radially inward projections 412 of the arms 408 slidealong the outer circumference of the trigger element 302 until theyreach the chamfered annular reinforcement rib 374 of the trigger element302. This can be seen in FIGS. 53a to 53d . In reaction to the furthermovement, as can be seen in FIGS. 54 a to 54 d, the arms 408 flex-out inradial outward direction once again, in order to overcome the chamferedannular reinforcement rib 374.

Having passed the chamfered annular reinforcement rib 374, the arms 408due to the inherent elasticity snap radially inwards and grip distallyright behind the chamfered annular reinforcement rib 374. The distalsurface of the chamfered annular reinforcement rib 374 is slightlyinclined such that it has a concave conical profile. In addition, theprojections 412 are correspondingly inclined, such that they engage intothis concave conical profile in a form-fitting manner. This engagementprevents any unintended further flexing out of the arms 408. Instead itkeeps the arms 408 engaging the concave conical distal surface of theannular reinforcement rib 374. Thereby, the shield retention indicator306 blocks any distal movement of the trigger element 302. As aconsequence any distal movement of the safety shield 102 is alsoblocked. This means, that the safety shield 102 having reached thecondition as shown in FIGS. 55a to 55d cannot be pressed into thelongitudinal housing 104.

This is shown in FIGS. 56a to 56d , which depict views according toFIGS. 44a to 44d in a condition in which the device is entirely removedfrom the injection site on the patient's skin, wherein the safety shieldis blocked against a further axial depression. Once a force is appliedin this condition onto the proximal portion 150 of the safety shield102, the arms 408 of the shield retention indicator 306 block any distalmovement. The shield retention indicator 306 in this situation issupported by means of the shield retention indicator inner element 314,in particular its endplate 456 against the bottom surface 532 of thedistal end cap 316. The letter, as mentioned above, is inseparablyconnected to the housing 104.

As a result, the safety shield 104 with its proximal portion 150 safelyand irreversibly covers the needle 206 against any misuse.

Benefits

The device 10 according to the above described example of the presentinvention inter alia has the following beneficial features:

-   -   The device 10 can be assembled easily from the three different        pre-assembled subassemblies syringe unit 100, pre-filled syringe        200 and power-pack 300.    -   The prefilled syringe 200 can be provided in different shapes        and sizes, which just requires an adaptation of the syringe        holder 106.    -   The distal end cap 50 can be easily removed from the housing        104, wherein the twisting-off operation is supported by the        action of the shield spring 304.    -   During the use of the device, the device gives an audible and/or        tactile and/or visible signal of the different states of        operation.    -   As long as the drug has not been delivered, the user can        recognize this state through the transparent housing 104 or a        window provided therein.    -   The device does not show any visible indicator until the drug        delivery is finished.    -   When the drug delivery has started by triggering the device by        means of pressing it against the patient's skin, there is no        possibility of stopping the delivery of the drug. This prevents        that the device is used plural times.    -   The device is easy and intuitively to use as it has no separate        trigger element, e.g. a button or the like. The triggering is        just caused by pressing the device with its safety shield 104        against the patient's skin.    -   The device has no rotating parts and no correspondingly        complicated rotational movements. This makes device simple to        manufacture and easy as well as reliable in use.

In summary, the device provides an easy to assemble structure with thepossibility of using different kinds of syringes. The device can beeasily and intuitively used in a failsafe manner. The device providesseveral feedback signals to the user.

Alternative Examples for Syringe Holder

FIGS. 57 and 58 show an alternative example for a syringe holder 600.The syringe holder 600 is formed by two longitudinal shells 602, 604,which form a longitudinal slit 606, 608 there between. The two shells602, 604 are connected by two flexible V-shaped arms 610, 612, on thedistal end the proximal portion, respectively, which provide flexibilityin circumferential direction to the syringe holder 600 and thereby allowthat the shells 602, 604 move elastically apart when introducing asyringe. The syringe holder 600 further comprises at its distal end 614and close to its proximal end 616 radial outward projecting structures618, 620 for fixing the syringe holder within a housing of anautoinjector.

In FIG. 58, one can see a radial inner projection 622, which is formedwithin both shells 602, 604, for supporting the syringe in axialdirection once plugged in from distal direction and received within thesyringe holder 600.

FIGS. 59 and 60 show a further alternative example of a syringe holder640. This syringe holder has a hollow cylindrical receiving tube 642with a distal end 644 and a proximal end 646. Similar to the exampleaccording to FIGS. 57 and 58, this syringe holder 640 also includesradial outward projecting structures 648, 650 in order to hold thesyringe holder within a housing of an autoinjector.

Close to its proximal end, the syringe holder is provided with twodouble-z portions 652, 654, which include inclined flexible arms 656,658 interconnected by a circumferential rib 660. At its innercircumferential surface, the syringe holder includes a radially inwardprojection 662, which is formed circumferentially within both flexibledouble-z portions 652, 654 for supporting the syringe in axial directiononce plugged-in from distal direction and received therein. In thissyringe holder 640, the syringe is pushed-in from its distal end 644with minor radial play within the hollow cylindrical receiving tube 642.For gripping the proximal front end of the glass body of the syringe,due to the elastic flexibility of the two double-z portions 652, 654,the arms 656, 658 slightly flex-out such that the circumferential ribs660 move in radial outward direction.

Both alternative examples for a syringe holder according to FIGS. 57 to60 have a circumferentially closed structure with features providingsome flexibility in radial or circumferential direction. Thereby, it ispossible to provide an easy assembling of the prefilled syringe with thesyringe holder. The syringe is held simply by flexing elements whichgive-in in radial outward direction. Thereby, tolerance variations ofthe glass syringe can be compensated both in radial outward direction aswell as axially. Nevertheless, the syringe holder has a robust structureby the shells or the cylindrical receiving tube.

FIG. 61 a shows an automatic mechanical drug delivery device 1010,formed as an auto-injector, according to the invention in a perspectiveside view. The device 1010 comprises a longitudinal body 1012 extendingalong an axis X and a removable end cap 1050 at the proximal end of thedevice. The end of the device 1010 to which the removable end cap 1050is located is called within this description the proximal end, whichwill be in contact with the patient. The opposite end, in FIG. 61 on theright side is called the distal end within this description.

A part of the body 1012 is covered by a label 1014, which extends from amiddle portion towards a distal end portion of the device 1010. In theready to use state shown in FIG. 61, one can see a tamper label 1016,which sticks to the body 1012 as well as the distal part of the end cap1050. When the end cap 1050 is removed, the tamper label 1016 breaks andthereby indicates that the end cap 1050 has been removed.

FIG. 61 furthermore schematically shows two different planes A and Brepresenting planes of longitudinal sections. In the following, whendescribing the structure and the operation of the device 1010, it isreferred to these particular planes of longitudinal sections.

FIG. 62 shows three subassemblies of the device 1010. On the left side,one can see the syringe unit subassembly 1100 including the end cap1050. Next to the syringe unit subassembly 1100, one can see asubassembly including a prefilled syringe unit 1200. On the right side,one can see a power-pack subassembly 1300. These three subassemblies1100, 1200 and 1300 are provided as separate preassembled modules whenassembling the device 1010 according to the invention. This allows topre-assemble the syringe unit 1100 and the power-pack 1300 and toprovide a corresponding prefilled syringe 1200 with a demandedmedicament provided therein in a sealed manner and with thepredetermined volume for drug delivery.

As will be seen in the following, the three subassemblies 1100, 1200 and1300 can be assembled to the device by plugging the prefilled syringe1200 into the receiving syringe unit 1100 and thereafter plugging thepower-pack 1300 from the right side into the open distal end of the body1012 of the syringe unit 1100 until it locks into a predeterminedposition. By this modular structure, the device according to theinvention can be easily assembled in an error-free manner.

It is to be noted that although in the following a particular example ofthe device 1010 is described in its structure and functioning in regardto the figures, the components of the device 1010 as described in thefollowing can be used also independently from the respective structure.In particular, each of the three subassemblies 1100, 1200 and 1300 andthe components thereof can be used separately and independently from theother subassemblies. For example the proximal subassembly 1100 and itscomponents can be used separately in another autoinjector, independentfrom the specific design of the syringe unit 1200 or the power-pack1300. Therefore, the following description is not to be understood as alimiting disclosure in a way that each and every component can only beused together with the further components described in the followingcontext. Instead, the present disclosure is to be understood in a waythat each and every component disclosed therein can be claimed with itsrespective features separately independent from the interactingcomponents of the respective subassemblies.

In the following the components of the subassemblies are described indetail.

FIG. 3 shows an exploded view of the syringe unit subassembly 1100. Thissyringe unit subassembly 1100 comprises the end cap 1050 formed by anend cap body 1052, a blade washer 1054 and a proximal end cap cover1056. Moreover, the syringe unit subassembly 1100 comprises a safetyshield indicator 1102, a safety shield 1104, a lock ring 1106, alongitudinal housing 1108 and a syringe holder 1110. These componentswill be described in detail in regard to FIGS. 66a to 73 in thefollowing.

FIG. 64 shows an exploded view of the components of the subassemblyforming the prefilled syringe 1200. This syringe subassembly includes arigid needle shield 1202, a glass body 1204 with an integrally providedneedle 1206, the medicament 1208 shown as a liquid column and a stopper1210. These components of the prefilled syringe 1200 will be describedin detail in regard to FIGS. 74 to 77.

FIG. 65 shows an exploded view of the components of the subassemblyforming the power-pack 1300. This power-pack subassembly 1300 includes aplunger 1302, a drive spring 1304, a shield retention trigger element1306 and a shield spring 1308. Moreover, the power-pack subassembly 1300comprises a shield retention indicator 1310, a retainer 1312, a rotaryclick element 1314 and a distal end cap 1316. These components will bedescribed in detail in regard to FIGS. 78a to 83b in the following.

FIGS. 66a and 66b show the end cap body 1052 from different perspectiveviews. One can see the cylindrical body having a number of integrallyformed radial gripping ridges 1058 extending in a longitudinal directionfrom the proximal end of the body 1052 to its middle portion. The distalpart is formed by a cylindrical body having smooth outer surface 1060.This surface includes arrow-shaped through holes 1059 which indicate thedirection of movement for twisting-off the end cap 1050 relative to thebody 1012. Moreover, one can see in FIGS. 66a and 66b two oppositeretaining ribs 1061 which are provided on the inner peripheral surfaceof the end cap body 1052 and which are interrupted by the through holes1059, respectively. These retaining ribs 1061 are provided to retain theend cap body 1052 on the housing 1108 when engaging into a U shapedprojection 1178, as will be discussed below in regard to FIG. 73.

In its interior, the end cap body 1052 includes an axially openreceiving portion 1062 with a smooth receiving surface. Next to thereceiving portion 1062 there is a portion having a formation of radialinwardly extending ribs 1064. Following to the portion including theribs 1064, the end cap body 1052 includes a step surface 66 abruptlyincreasing the inner diameter of the end cap body 1052. The step surface1066 follows in axial direction a closed sinus shape acting as a drivingcurve when it comes into engagement with a corresponding drivingprojection of the housing 1108 for twisting-on or twisting-off the endcap 1050 relative to the body 1012. In the distal portion the interiorof the end cap body 1052 includes further radially inwardly extendingribs 1068 acting as contact means, which interact with the outercircumferential surface of the housing 1108.

FIG. 67 shows the cap cover 1056. It includes a cylinder with an outercircumferential surface 1070 in order to be introduced into the actuallyopen receiving portion 1062 of the end cap body 1052 with a press-fitengagement. The cap cover 1056 has a closed proximal end wall 1072.Axially extending from this end wall 1072 in distal direction, the capcover 1056 provides an inner cylindrical ring 1074 with a formation ofradially inner ribs 1076. The distal end surfaces 1078 of the inner ribs1076 are slightly sloped inwardly to form a circumferential bevel.

FIG. 68 shows the blade washer 1054. The blade washer 1054 has acircular outer circumference 1080 surrounding a ring-shaped body 1082.The blade washer 1054 includes four radially inwardly extending lobes1084 integrally formed with the ring-shaped body 1082 and ending in acircular radially inner gripping surface 1086. In a side view, one cansee that the blade washer 1054 has a frusto-conical shape, wherein thelobes 1084 provide an axial spring action, i.e. the lobes 1084 can bedeflected elastically in axial direction.

Generally, the external geometry 1080 of the blade washer 1054 may be ofcircular or any other geometry to suit assembly loads or packaging spaceavailable. There may be two or more extending lobes 1084 and the bladegeometry may be of any format to achieve certain insertion forces and ofany ability to hold forces from the rigid needle shield when the end capis removed from the housing. Generally, the blade washer 1054 may have aplanar or flat shape. In other examples the blade washer could also havesome non-planar pre-forming, e.g. it can be formed conical or wave-like.It may be possible in an example to form a rib around the outer rim ofthe blade washer to enforce it. This may be to allow rotation of theblade washer during cap removal. If the cap rotates and the blade washeris only pulled longitudinally a detrimental condition called coring canbe eliminated. Coring occurs where the rubber of the rigid needle shieldis rotated around the needle. It may then be possible for a plug ofrubber to remain inside the needle, which is undesired. This may cause ablockage stopping the device from functioning correctly.

In an assembled state of the end cap 1050, the blade washer 1054 isarranged on the proximal surface of the ribs 1064 and is clamped againstthe ribs 1064 by pressing the cap cover 1056 into the receiving portion1062. The blade washer 1054 is thereby fixedly held or arranged withsome axial clearance between a front surface 1086 of the cylindricalradially outer portion of the cap cover 1056 and the ribs 1064, in orderto allow axial resilient deflection for gripping the rigid needle shield1202 described below. The inner ring 1074 is arranged in sufficientdistance to the lobes 1084 such that the lobes can flex proximally inaxial direction.

FIGS. 69a and 69b show the safety shield 1104 in different perspectiveviews. The safety shield 1104 includes a ring-shaped body 1112 with twodiametrically opposing longitudinal arms 1114, 1116. The ring-shapedbody has a stepped and rounded outer surface profile such that itdecreases in diameter from a cylindrical portion 1118 to a projectingrounded front end portion 1120 having an axial opening 1122. The innerdiameter of axial opening is slightly larger than the outer diameter ofthe rigid needle shield 1202 in order to allow a frictionless movementof the syringe together with the rigid needle shield 1202 therethrough.The front end portion 1120 of the safety shield 1104 is rounded and freeof sharp edges and provided for getting in contact with the patient'sskin. Moreover, the safety shield 1104 of the device 1010 according tothe present invention forms the trigger element when being pressed witha required triggering force against the patient's skin. Therefore, thisfront end portion 1120 his smoothly formed such that it does not injureor scrape on the patient's skin.

The two longitudinal arms 1114 and 1116 have a slightly rounded shapeand include next to the cylindrical portion 1118 a longitudinal slottedthrough hole 1124, respectively. Hence, the two through holes 1124 areprovided in opposing position relative to one another. These throughholes 1124 act as guiding means for guiding a longitudinal movement ofthe needle shield 1104 within the device 1010.

The ring-shaped body 1112 of the needle shield 1104 includes fourradially inwardly extending ribs 1126. These inner ribs 1126 areprovided in order to support the rigid needle shield 1202 againstdeflections and thereby support the position of the prefilled syringe1200 in an assembled state, i.e. during transportation. Moreover, thering-shaped body 1112 of the needle shield 1104 includes two opposedthrough holes 1128 with a proximal wall 1129 and a distal wall 1130,each running in substantially perpendicular direction to the main axisX.

FIG. 70 shows the safety shield indicator 1102. The safety shieldindicator 1102 is formed as a thin-walled element which is connectableto the proximal ring-shaped body 1112 of the needle shield 1104 by apress-fit and/or snap-fit engagement. As an alternative, the safetyshield indicator can be just provided as a colored coating on the frontsurface of the needle shield 1104 or may be integrally molded as acolored portion of the needle shield 1104. To this purpose, the safetyshield indicator 1102 has an inner surface profile corresponding to theouter surface profile of the ring-shaped body 1112 of the needle shield1104. The safety shield indicator 1102 is provided with acircumferential outer surface having a signalling color, i.e. yellow,orange or red, which is clearly visible by a user. Thereby, as will bediscussed in detail in regard to the operation of the drug deliverydevice 1010 according to the present invention, the user, i.e. themedical practitioner or the patient, of the device 1010 can easilyrecognize when the safety shield indicator 1102 protrudes out of thehousing 1108 and covers the needle 1206.

FIGS. 71a and 71b show the structure of the lock ring 1106. The lockring 1106 is provided to engage with the safety shield 1104 during useas the safety shield 1104 is fully pressed into the housing 1108 whenthe device 1010 is triggered to deliver the medicament to the patient.After engagement with the safety shield 1104, the lock ring 1106 ispermanently coupled to the safety shield 1104 and prevents the safetyshield 1104 from being pushed back a second time into the housing 1108when the device has been used and after the drug has been fullydelivered.

The lock ring 1106 includes a closed ring 1132 with two opposingrecesses 1134. Radially inside of these recesses 1134, the lock ring1106 is provided with two flexible arms 1136, formed on opposing lobes1138 protruding radially inwardly from the lock ring. In addition, thelock ring includes two further radially inwardly projecting lobes 1140.The two flexible arms 1136 protrude in proximal direction and have aradially outwardly extending snap lug 1142, respectively. Moreover, atthe proximal end, flexible arms 1136 have a front surface runningsubstantially in radial direction.

In other examples the ring may be of a different sectional geometry andthe number of legs may be singular to multiple.

On the distal side of the closed ring 1132, the lock ring 1106 isprovided with four slightly flexible arms 1146 extending in distaldirection. Each of the flexible arms 1146 has a snap lug 1148 on itsdistal end extending radially inwardly with a slightly inclined distalwall 1150. Thereby, each flexible arm 1146 provides a sharp toothprofile on its distal end. It is important to mention that the degree offlexibility of the arms 1146 is to be adapted to the spring rate of thespring 1308, such that the slide over forces of these arms 1146 are lessthan the safety shield spring force. This is to ensure that the lock outafter injection and the removal of the device from the skin alwaysworks. This will be discussed in the following when the functioning isdescribed.

FIGS. 72a and 72b show one example for the syringe holder 1110. Thesyringe holder 1110 has the purpose to receive and hold the prefilledsyringe 1204 within the housing 1108. It is adapted to receive differentkinds of syringes with different volumes of the medicament without theneed of substantially changing the dimensions of other components of thedevice 1010. Therefore, different sizes for syringe holders 1110 are tobe provided in adaptation to the different kinds of syringes.

The syringe holder 1110 provides a longitudinal tube-like body 1152. Atits proximal end, the tubular body 1152 has four projecting flexiblearms, wherein each arm 1154 of a first pair of two opposing arms 1154has a radially inwardly projecting lug 1156 forming a gripping element.Each arm 1158 of a second pair of the two opposing arms 1158 as abevelled lug 1160 which is supported by means of a crossing transversesupport rib 1162. The bevelled lug 1160 is provided with an inclinedsurface 1164 on its proximal portion. The distal end of the syringeholder 1110 has an angled collar 1166 with two recesses 1168 on oppositesides thereof. The collar 1166 has a radial portion 1170 and alongitudinal portion 1172 which are connected by a rounded thetransition. The radial portion 1170 can be rounded or chamfered at itstransition to the longitudinal portion 1172 in order to facilitate theassembly, in particular the introduction of the syringe holder 1110together with the syringe 1200 into the housing 1108.

FIGS. 73a to 73c show the housing 1108 in different views. The housing1108 has the purpose of forming the main body 1012 of the device 1010.It is formed from a stable, rigid, transparent or opaque material. Ifnot entirely transparent, the housing can be formed with drug viewingcutouts or transparent windows in order to make the drug and the actualstate of the device visible to a user. The housing 1108 is formed by alongitudinal tubular member 1174. At its proximal end, the tubularmember is provided with a front surface 1176 having a closed sinusshaped contour. Close to the proximal end and the front surface 1176,the housing 1108 is provided with two U-shaped lateral projections 1178,which are arranged opposite to one another and project radiallyoutwardly. The U-shaped lateral projections 1178 are provided to receivethe retainer ribs 1061 of the end cap body 1052, described in regard toFIG. 66a , in order to retain the end cap body 1052 before use inposition on the housing 1108. At its distal end, the housing has acircular front surface 1180. Close to the end surface and insubstantially longitudinal alignment with the projections 1178, thehousing 1108 has two opposing transverse slits 1182. In the regionbetween the distal end and the slits 1182, the housing is integrallyformed with two pairs of projecting knobs 1184. The projecting knobs1184 can also have an alternative shape. They have the function toprovide anti-rolling features of the device 1010 on a flat surface. Eachpair of knobs 1184 is aligned with the respective transverse slit 1182.

In its interior, the housing 1108 is provided with a ring structure1186, which is integrally connected with the tubular member 1174 bymeans of pair of opposing rigid connecting arms 1188. The connectingarms 1188 are formed by a stable E-like structure with threelongitudinal connecting ribs and one transverse connecting rib. The sizeof the connecting ribs and the E like sectional shape are to providestructural rigidity to the housing 1108. This joining geometry is alsoimportant for the flow of the material when the component is molded.Moreover, the ring structure 1186 has a longitudinal crest 1190, withtwo V-shaped cutouts 1192 opening in distal direction and terminating inproximal direction at a radial circular base surface 1194. The V-shapedcutouts 1192 provided for receiving the bevelled lugs 1160 with thetransverse support ribs 1162 of the syringe holder 1110. A longitudinalcollar 1196 extends in proximal direction from the base surface 1194.This geometry guides the movement of the safety shield 1104 during theoperation of the device 1010 and, furthermore, locates the syringeholder 1110 in place within the housing 1108. The collar 1196 has alevel of rigidity to restrain the loads applied through the syringe 1200when the device is activated, as will be discussed below.

FIGS. 74 and 75 show perspective views of the rigid needle shield 1202and an insert 1212 thereof. The rigid needle shield 1202 is formed by atubular member 1214 with an open distal end 1216 and a closed proximalend 1218. In its front portion it has a surface formed with transversegripping ribs 1220. Close to its distal end, it has two oppositerectangular through holes 1222.

The insert 1212 shown in FIG. 75 is formed by a soft deformable materialand can be pressed into the rigid needle shield 1202 such that it isfixedly held therein. It has an annular collar 1224 close to its distalend which engages with the rectangular through holes 1222 of the rigidneedle shield 1202.

FIG. 76 shows the syringe 1204. The syringe 1204 is formed by a hollowcylindrical glass body 1230 having an open distal end 1232, which issurrounded by a circumferential annular collar 1234 with two flattenedopposite side surfaces 1235. At its proximal portion, the cylindricalglass body 1230 is formed with a rounded taper 1233 and transits into ahollow conical glass portion 1236. The hollow conical glass portion 1236terminates in a proximal head 1238, in which said needle 1206 with asharpened needle tip 1240 is fixedly received.

FIG. 77 shows the stopper element 1210 formed from a flexible material,e.g. a rubber. At its proximal portion, it has a smooth cylindricalouter circumferential surface 1242, which has a diameter adapted to theinner diameter of the hollow cylindrical glass body 1230 of the syringesuch that the stopper element 1210 slidably engages the innercircumferential surface of the hollow cylindrical glass body 1230 in afluid tight manner. On the distal portion of the outer surface, thestopper element 1210 is provided with four circumferential annularrecess is forming three circumferential sealing the ribs 1244. Thestopper element 1210 has cup-shape with a closed proximal end 1246 andan open distal end 1248.

Turning now to the components of the power-pack, FIGS. 78a and 78bdepict the plunger 1302 in different perspective views. The plunger 1302is formed by a longitudinal pipe shaped hollow element 1320 which has atits proximal end a plunger head 1322. The plunger head 1322, which canbe formed integrally with the hollow element 1320 or as a separatepiece, has a cylindrical portion 1324 with an enlarged outer diameter inthe example shown. This enlarged plunger head 1322 is used for largersyringes, e.g. having a drug volume of 2.25 ml instead of only 1 ml. Incase of smaller syringes, e.g. having a drug volume of 1 ml, theenlarged plunger head 1322 can be omitted and the plunger 1302 has juststraight cylindrical shape on its proximal end. In the middle portion ofthe plunger 1302, a pair of opposing rectangular through holes 1326 isprovided in the wall of the hollow element 1320. At the distal end, thehollow element 1320 is provided with four longitudinal ribs 1328,equidistantly arranged around the circumference of the hollow element1320. Moreover, the distal end of the plunger 1302 provides two slottedpathways 1330 opening to the distal end face 1331, each having aninclined portion 1332 and a longitudinal end portion 1334.

FIGS. 79a and 79b depict the shield retention trigger element 1306. Theshield retention trigger element 1306 is formed by a hollow bushing 1340having a radial annular collar 1342 integrally formed at its proximalend. The bushing 1340 is provided with two opposite slits 1344 openingto its distal end. The two opposite slits 1344 provide longitudinalguiding surfaces 1346 extending through the entire bushing 1340.

FIGS. 80a and 80b depict the shield retention indicator 1310. The shieldretention indicator 1310 has the purpose of providing a visibleindicator for the actual state of use, in particular an indicatorshowing that the device 1010 was already used for delivering a drug. Itcomprises an annular cylindrical body 1350, having at its proximal innercircumferential surface radially inwardly protruding ribs 1352.Moreover, the annular cylindrical body 1350 has two opposing flexiblearms 1354 extending in proximal direction, wherein a first portion 1356runs in longitudinal direction, a second portion 1358 is inclinedradially inwards, and a third portion 1360 extends in longitudinaldirection, however, on a level which is further radially inward then thefirst portion 1356. At its proximal end, each of the arms 1354 has aretaining projection 1362 extending radially outwards.

In its middle portion, the annular cylindrical body 1350 has an annularflange 1364 extending in radial outward direction. Two opposite arcuatewall members 1366 extend in distal direction from the flange 1364. Theouter circumferential surfaces 1368 of these arcuate wall members 1366are provided with a signalling color and/or a signalling visiblepattern.

FIGS. 81a and 81b depict the retainer 1312 of the power-pack 1300. Theretainer 1312 acts as the control member including a plurality ofcontrol functions of the power-pack 1300. The retainer is formed from ahollow cylindrical body 1370. On two opposing sides the cylindrical body1370 includes a U-shaped cutout 1372 forming a longitudinal flexible arm1374. The longitudinal flexible arm 1374 is integrally connected withthe hollow cylindrical body 1370 at its distal end 1376. At its proximalend, the flexible arm 1374 is provided with a chamfered radial outwardprojection 1378 and, on the opposite side, with a correspondingchamfered radial inward projection 1380. Moreover, the cylindrical body1370 is provided with two opposing longitudinal cutouts 1382 in an arearotated by 90° relative to the flexible arms 1374 formed by the cutouts1372. The longitudinal cutouts 1382 extend approximately with the samelongitudinal extension as the U-shaped cutout 1372. In the region ofabout one third of the longitudinal length of the cutouts 1382 close totheir proximal end, the cylindrical body 1370 comprises lateralprojections 1384 transversely bridging the cutouts 1382.

At its proximal end, the cylindrical body 1370 is provided with twoflexible arms 1390 integrally formed with the cylindrical body 1370 andinclined by an angle of about 45° relative to the proximal front surfaceof the hollow cylindrical body 1370. These flexible arms 1390 areconnected with a ring-shaped head portion 1392. The ring-shaped headportion 1392 is formed as a bushing with a cylindrical portion 1394 anda proximal flange portion 1396. The head portion 1392 can be integrallyformed with the flexible arms 1390 or formed as a separate piece fixedlyconnected to the flexible arms 1390, e.g. by means of an intermediateconnecting ring.

At its distal end, the cylindrical body 1370 is formed with two opposinggroups of outer longitudinal ridges 1400, 1402, 1404, extending inradial outward direction from the cylindrical body 1370. Distally fromthe ridges 1400, 1402, 1404, the cylindrical body 1370 includes acylindrical portion 1406 with increased diameter. This cylindricalportion 1406 with increased diameter includes two opposing roundedlateral cutouts 1408, which are aligned in longitudinal direction withthe cutouts 1382 of the cylindrical body 1370. The remaining non-cutoutwall sections of the cylindrical portion 1406 are provided with twolongitudinal projections 1410 extending slightly in radial outwarddirection and having a rectangular shape when viewed in a side view.These projections 1410 are provided with a transverse slot 1412 in theirmiddle portion, respectively.

FIGS. 82a and 82b depict the rotary click element 1314. The rotary clickelement is provided for changing the driving force of the main spring1304. It is formed by a hollow cylindrical bushing 1420, having a smoothproximal front surface 1422 and a distal surface formed with an annularcrest of shark teeth 1424. Radially inward from the crest of shark teeth1424, the rotary click element 1314 includes two opposing cylindricallyshaped wall portions 1426 which are divided by a transverse slit 1428.On the inner circumferential surface, the bushing 1420 is provided withprojections for engaging the main spring 1304 for a common rotationtherewith.

FIGS. 83a and 83b depict the distal end cap 1316 of the device 1010. Thedistal end cap 1316 has a distal plate-formed end cap body 1440 closingthe distal opening of the housing 1108. For that purpose, the end capbody 1440 is formed with two projecting flexible arms 1442 havingengagement projections 1444 on their proximal ends. These flexible arms1442 act as snap hooks engaging with the corresponding openings 1182 ofthe housing 1174. Moreover, radially inwards from the flexible arms1442, the end cap body 1440 is formed with a hollow cylindrical body1446. The hollow cylindrical body 1446 is provided with two opposingnose elements 1448, which extend in radial outward direction. Moreover,the hollow cylindrical body 1446 is provided with two proximal slopes1450 extending in longitudinal direction. Inside the hollow cylindricalbody 1446, on the surface of the end cap body 1440, there is provided afurther crest of shark teeth 1452 adapted to engage the crest of sharkteeth 1424 formed on the rotary click element 1314. A longitudinalcylindrical rod member 1454 extends in the centre of the crest of sharkteeth 1452 from the surface of the end cap body 1440 in proximaldirection.

In the following, the assembled state of the device 1010 is described inregard to FIGS. 84a and 84b . This is also the initial state of thedevice 1010, i.e. the state of the device how it is delivered to theuser. In the assembled state of the device 1010 the end cap 1050 isremovably fixed to the longitudinal housing 1108, wherein the end cap1050 is held with its retaining ribs 1061 and the corresponding recesswithin the U-shaped projections 1178 of the housing 1108. The syringe1204 is held within the syringe holder 1110, which is received in thering structure 1186 of the housing 1108. Moreover, the syringe 1204 ispressed via its annular collar 1234 or flange by means of the headportion 1392 in proximal direction against the ring structure 1186 ofthe housing 1108, wherein the flexible arms 1390 act as a spring meansproviding a spring force in axial direction in order to hold the syringe1204 in place within the syringe holder 1110. The rigid needle shield1202 engages the hollow conical glass portion 1236 by means of theinsert 1212. The soft insert 1212 safely covers the needle 1206 andmaintains sterility of the contact needle and contained medicament. Asone can see, the outer surface of the tubular member 1214 with thetransverse gripping ribs 1220 is engaged by the flexible lobes 1084 ofthe blade washer 1054. The blade washer 1054 is held within the 1050 bymeans of the cap cover 1056.

Moreover, FIG. 84b shows the ring-shaped body 1112 of the safety shield1104. The safety shield 1104 is pressed by the end cap 1050 via thelongitudinal arms 1114, 1116 against the force of the shield spring1308, wherein the shield retention trigger element 1306 acts as aninterface between the longitudinal arms 1114, 1116 and the shield spring1308. The proximal end of the shield spring 1308 engages against theflange 1342 of the shield retention trigger element 1306, wherein thedistal end of the shield spring 1308 presses against the flange 1364 ofthe shield retention indicator 1310.

The shield retention indicator 1310 is held by means of its arms 1354 inits axial position in spite of the compressed shield spring 1308 and theresulting forces. This is achieved due to the fact that the arms 1354reach through the longitudinal cutouts 1382 of the retainer 1312 andengage with their radial retaining projections 1362 behind the lateralprojections 1384 bridging the cutouts 1382 of the retainer 1312.Moreover, in this state, the plunger 1302 arranged radially inside thearms 1354 prevents that the arms 1354 flex radially inwards.

The plunger 1302 retains the main spring 1304 in a compressed state. Theproximal end of the main spring 1304 presses against the proximal end ofthe plunger 1302 to which the plunger head 1322 is fixed. One can seethat the plunger head 1322 is slidably received within the hollow glassbody 1230 of the syringe 1204 close to the stopper element 1210.Moreover, FIG. 84b shows the medicament 1208 as a liquid column includedwithin the syringe 1204.

The distal end of the main spring 1304 protrudes out of the plunger 1302and is received within the hollow interior of the rotary click element1314, where it is also engaged in a non-rotatable manner. The rotaryclick element 1314 in turn is received within the hollow cylindricalbody 1446 of the distal end cap 1316, wherein the two shark teethformations 1424 and 1452 engage with one another. A relative rotation ofthe rotary click element 1314 and the distal end cap 1316 causesclicking sounds, which are audible or sensible by the user.

As can be seen in FIG. 84b on the right side, the cylindrical polemember 1454 extends in proximal direction into the hollow interior ofthe main spring 1304 and acts as an axial guiding element for thecompressed main spring 1304. The distal end cap 1316 is plugged into thehousing 1108, wherein the flexible arms 1442 with their radiallyoutwardly pointing engagement projections 1444 are engaged with thetransverse slits 1182 of the housing and they thereby hold the distalend cap 1316 in place against resulting spring forces.

From this fully assembled initial position, the device 1010 according tothis example of the invention is used as follows:

In order to remove the end cap 1050, it is twisted-off from the housing1108 according to the direction of the arrow-shaped opening 1059.Thereby, the temper label 1016 is ruptured. The twisting-off force mustbe large enough in order to overcome the interaction between the Ushaped projections 1178 on the housing 1108 receiving the retaining ribs1061 provided on the inner surface of the end cap body 1052. Thetwisting-off movement follows the profile of the sinus shaped frontsurface 1176 of the housing 1108. Due to the fact that the safety shield1104 in the ready to use state is biased by the shield spring 1308against the end cap 1050, the twisting-off movement of the end cap 1050is supported by this biasing force of the shield spring 1308. Thereby,after overcoming an initial resistance also provided by the tamper label1016, the twisting-off movement of the end cap 1050 is supported by thespring force and the user experiences a supported removal of the end cap1050. During the removal of the end cap 1050, while it supports thetwisting-off movement of the end cap 1050, the shield spring 1308expands in axial direction and presses the safety shield 1104 out of thehousing 1108 until it finally reaches its fully extended position, whereit covers the needle 1206. Moreover, during the removal of the end cap1050, the rigid needle shield 1202 which is gripped by the lobes 1084 ofthe blade washer 1054, is withdrawn together with its insert 1212 fromthe hollow conical glass portion 1236 of the syringe 1204. Thereby theneedle 1206 with its needle tip 1240 is exposed within the ring-shapedbody 1112 of the safety shield 1104.

In other words, the removable end cap 1050 is retained to the housing1108 by the U shaped projection 1178. This is shown as a U in shape butmay be of a number of other geometrical formats. Its function is arestraint on the middle of the U. This sets the pull-off force for theremovable end cap 1050 if pulled. The removable end cap 1050 has theribs 1061 in the middle of the arrow cut out that contacts the middle ofthe U-shaped projection 1178. The respective angle aligned which stopspull-off and to angles which, when larger, require less pull-off forces.The ability of the plastic region of the arrow cut-out 1059 and theangle in combination allow tuning the pull-off force to the requiredlevels. Rotationally the sides of the U-shaped projection 1178 areangled to tune the initial torque required to start removal of theremovable end cap 1050. The longitudinal and rotational restraints ofthe U-shaped projection 1178 and restraining rib 1061.

FIGS. 85a and 85b show longitudinal sectional views of the drug deliverydevice according to the example of the present invention in a statewhere the end cap 1050 has just been completely removed, wherein FIG.85a is the longitudinal section along plane A indicated in FIG. 61 andwherein FIG. 85b is the longitudinal section along plane B indicated inFIG. 61.

In this state, the safety shield 1104 projects with its ring-shaped body1112 out of the housing 1108. The user can see the safety shieldindicator 1102 with its signalling color protruding out of the housing.The shield spring 1308 is in a partially relaxed but still substantiallyconstrained state. The main spring 1304 is still fully compressed and itis kept in this fully compressed state due to the fact that the flexiblearms 1374 of the retainer 1312 engage with the chamfered radial inwardprojections 1380 into the opposing rectangle of through holes 1326 ofthe plunger 1302. Thereby, the plunger 1302 is held against the springforce of the main spring 1304 in axial position preventing an expansionof the main spring 1304. The power-pack 1300 is preloaded.

The possible range of axial movement of the safety shield 1104 isdetermined by the length of the longitudinal slotted through holes 1124in each of the longitudinal arms 1114, 1116, which receive the bevelledlugs 1160 of the syringe holder 1110. This can also be achieved in analternative way, i.e. by projections guided in longitudinal slots withinthe housing 1108 or the like. As discussed above, in the assembled statethe syringe holder 1110 is fixedly retained within the housing 1108.

For using the device 1010, as shown in FIGS. 85a and 85b , the device ispositioned on the patient's skin S at a location, where the patientintends to inject the medicament, e.g. against a thigh of the patient.The device 1010 is then pushed by the user in proximal direction ontothe patient's skin S. Thereby, the safety shield 1104 is pressed intothe housing 1108 against the biasing force of the shield spring 1308,while—due to the pushing movement of the device—the needle tip 1240penetrates the patient's skin S and the needle 1206 is pushed throughthe patient's skin S into the patient's tissue. Finally, when it isfully depressed into the housing 1108, the safety shield 1104 hits withthe distal end surface of its ring-shaped body 1112 against the proximalfront surface of the connecting arms 1188, which connect the housing1108 with the ring structure 1186. At this point, no further axialmovement of the safety shield 1104 into the housing 1108 is possible andthe safety shield 1104 is blocked.

This position of a fully depressed safety shield 1104 is shown in FIGS.86a and 86b depicting longitudinal sectional views of a state, when thedrug delivery device is just fully pressed against the patient's skinand the drug delivery through is just started.

In this state, the two flexible arms 1136 of the lock ring 1106 engagewith their snap lugs 1142 into the corresponding openings 1128 of thering-shaped body 1112 of the safety shield 1104. Thereby, the lock ring1106 is fixedly coupled to the safety shield 1104 providing a commonmovement in axial direction during further use. Moreover, in this state,the safety shield indicator 1102 is mainly covered by the housing 1108,as the ring-shaped body 1112 is substantially received within thehousing 1108.

As can be seen in FIG. 86b , by pushing the safety shield 1104 into thehousing, the two longitudinal arms 1114, 1116 are moved in distaldirection while they are guided by the engagement of the bevelled lugs1160 and the slots 1124. Thereby the shield retention trigger 1306 ismoved against the compression force of the shield spring 1308 in distaldirection. The shield retention trigger 1306 is moved in distaldirection to such an extent that it unblocks the chamfered radialoutward projections 1378 of the flexible arms 1374 of the retainer 1312.As a consequence, the flexible arms 1372 are free to flex in radialoutward direction. Due to the biasing of the main spring 1304 pressingthe plunger 1302 in proximal direction and due to the chamfered designof the radial inward projections 1380 interacting with thecorrespondingly chamfered rim of the through holes 1326 of the plunger1302, the flexible arms 1374 are forced radially outwardly by theplunger 1302 and thereby disengage from the openings 326. In thefollowing, the plunger 1302 can move in proximal direction, contact thestopper element 1210, shift the stopper element 1210 in proximaldirection within the glass body of the syringe 1204 and startdelivering, i.e. pressing out, the medicament through the needle 1206into the patient's tissue.

FIGS. 87a and 87b show longitudinal sectional views in an intermediatestate, when the drug delivery device delivers the drug to the patient,wherein the plunger 1302 has contacted the stopper element 1210 and hasmoved it within the syringe 1204 over a certain distance to press outthe medicament through the needle. In FIG. 87b , one can clearly seethat the flexible arms 1374 have been bent radially outwardly andreleased the openings 1326. As a matter of course, the plunger 1302 ismoved in proximal direction under the spring force of the main spring1304, which tends to expand.

Finally, the main spring 1304 has driven the plunger 1302 and therebythe stopper element 1210 in immediate proximity to the rounded taper1233 of the syringe 1204. FIGS. 88a and 88b show longitudinal sectionalviews depicting this state, when the drug delivery is close to an end.In this state, the distal end of the plunger 1302 with its end face 1331just passes the proximal side of the radial inwardly extendingprojections 1380 of the flexible arms 1374 of the retainer 1312. Whenthe end face 1331 of the plunger 1302 passes the proximal side of theprojections 1380, the flexible arms 1374 can flex radially inwardsbehind the end face 1331. Moreover, this radially inward movement of theflexible arms 1374 may provide a certain audible and or tactile signalto the user, as the proximal front portion of the flexible arms 1374hits the circumferential outer surface of the distal end of the plunger1302.

Moreover, as can be seen in FIG. 88b , in this state close to the end ofthe drug delivery with the plunger 1302 nearly fully advanced inproximal direction within the syringe 1204, the plunger 1302 has alsopassed with its distal end surface 1331 the proximal end of the flexiblearms 1354 of the shield retention indicator 1310. Thus, the plunger 1302unblocks in radial inward direction the flexible arms 1354 of the shieldretention indicator 1310. As a consequence, due to the biasing force ofthe compressed shield spring 1308, the chamfered retaining projections1362 of the arms 1354 slide along the proximal front surface of thelateral projections 1384 transversely bridging the cutouts 1382 of theretainer 1312. Thereby, the flexible arms 1354 are forced radiallyinwardly and flex inwards. The flexible arms 1354 are now free to passthe lateral projections 1384 in distal direction. As the compressedshield spring 1308 tends to expand, it moves the shield retentionindicator 1310 in distal direction until it hits the distal end cap 1316resulting in an audible and/or tactile signal being given to the user.

Moreover, the opposite arcuate wall members 1366 with their outercircumferential surfaces colored with a signal color enter into the freecircumferential space between the flexible arms 1442. As mentionedabove, the housing 1108 is formed from a transparent material. The label1014 ends in a substantial distance, e.g. a distance of more than 6 to20 mm, from the proximal end of the housing 1108 providing thereby acircular transparent window 1198 allowing the user to see the interiorof the housing 1108.

In the states shown in FIGS. 84a, 84b to 87a, 87b , the window is clear.However, as shown in FIG. 89b , as soon as the shield retentionindicator 1310 is released by the radial inward movement of the arms1354 and pressed by the shield spring 1308 in distal direction, theaccurate wall members 1366 with the colored or patterned circumferentialsurfaces 1368 enter into the circumferential free space and are visiblethrough said circular transparent window 1198. Thereby, the user alsoreceives a visible indication in the window 1198 indicating that thedrug delivery has come to an end. In another example this could be oneor a plurality of windows if the label or housing created opaque andclear regions.

FIGS. 89a and 89b show longitudinal sectional views in a state, when thedrug delivery device has fully delivered the drug to the patient. Onecan see, that the main spring 1304 is substantially relaxed and haspressed the plunger 1302 together with the stopper element 1210 fullyagainst the inner surface of the rounded taper 1233 of the syringe 1204.The medicament is fully pressed out through the needle 1206 into thepatient's tissue. The shield retention indicator 1310 this pressed bythe shield spring 1308 fully to the distal end and can be seen throughthe window 1198 by the user.

The user knows by the audible and/or tactile signal as well as by thevisual indication through the window 1198 that the drug delivery hascome to an end. The user then removes the device 1010 from its skin byretracting it in axial direction, thereby withdrawing the needle out ofits tissue. While removing the device 1010 from its skin, i.e. whilewithdrawing the needle out of its tissue, the a safety shield 1104remains in permanent contact with the patient's skin S until it fullycovers and protrudes over the needle 1206 with its needle tip 1240. Thisis due to the fact that the needle shield is pressed by the shieldspring 1308 together with the shield retention trigger element 1306 inproximal direction out of the housing 1108.

FIGS. 90a to 90c show different views of a state, when the drug deliverydevice was removed from the patient's skin and secured in a locked stateafter use. The safety shield 1104 which is permanently coupled to thelock ring 1106 (see FIG. 86a ) protrudes out of the housing 1108. Thelock ring 1106 engaging by means of its flexible arms 1136 with thecorresponding openings 1128 in the ring-shaped body 1112 blocks thesafety shield 1104 against any further distal movement within thehousing 1108. In other words, the lock ring 1106 prevents that thesafety shield 1104 is pressed back into the housing. Thereby, the safetyshield 1104 safely covers the needle 1206 with its needle tip 1240,which is contaminated with patient's blood, against any manipulation orany contact with a patient or practitioner.

The blocking of the safety shield 1104 against any movement in distaldirection is achieved by the four flexible arms 1146 formed on thedistal side of the lock ring 1106. When the safety shield 1104 ispressed out of the housing 1108 under the force of the shield spring1308 while the device 1010 is removed from the insertion site on thepatient's skin, due to the permanent coupling of the arms 1136 with thesafety shield 1104 the safety shield 1104 entrains the lock ring 1106with this movement. Thereby, the lock ring 1106 is moved with its fourflexible arms 1146 across the outer circumferential surface of the ringstructure 1186 integrally formed within the housing 1108. Finally, theflexible arms 1146 pass with their distal wall 1150 the proximal frontedge of the ring structure 1186 of the housing 1108 and flex radiallyinwards. Thereby, the four flexible arms 1146 with their distal wall1150 snap radially inwards in front of the proximal surface of the ringstructure 1186. As a consequence, the flexible arms 1146 act as fixedspacers between the safety shield 1104 and the proximal front surface ofthe ring structure 1186. By means of the lock ring 1106, the safetyshield 1104 is secured against any relative distal movement into thehousing 1108. Moreover, the safety shield 1104 is also secured againstany further proximal movement out of the housing 1104, i.e. againstbeing withdrawn out of the housing, as it is blocked by means of theradial distal surface of the bevelled lugs 1160 engaging into thelongitudinal slots 1124 of the arms 1114, 1116.

Thereby, any further use of the device 1010 is prevented. It is also notpossible to screw or push the end cap 1050 onto the housing 1108, as itis blocked by the protruding and lock safety shield 1104. The user cansee the colored shield indicator 1102 as well as the colored wallsegments 1366 of the shield retention indicator 1310 through the window1198.

The device 1010 according to the above described example of the presentinvention inter alia has the following beneficial features:

-   -   The device 1010 can be assembled easily from the three different        pre-assembled subassemblies syringe unit 1100, pre-filled        syringe 1200 and power-pack 1300.    -   The prefilled syringe 1200 can be provided in different shapes        and sizes, which just requires an adaptation of the syringe        holder 1110.    -   The distal end cap 1050 can be easily removed from the housing        1108, therein the twisting-off operation is supported by the        action of the shield spring 1308.    -   During the use of the device, the device provides plural        possibilities of giving an audible and/or tactile and/or visible        signal of the different states of operation.    -   As long as the drug has not been delivered, the user can        recognize this state through the window 1198 which does not show        any visible indicator until the drug delivery is finished.    -   When the drug delivery has started by triggering the device by        means of pressing it against the patient's skin, there is no        possibility of stopping the delivery of the drug. This prevents        that the device is used plural times.    -   The device is easy and intuitively to use as it has no separate        trigger element, e.g. a button or the like. The triggering is        just caused by pressing the device with its safety shield 1104        against the patient's skin.

In summary, the device provides an easy to assemble structure with thepossibility of using different kinds of syringes. The device can beeasily and intuitively used in a failsafe manner. The device providesseveral feedback signals to the user.

1. An automatic drug delivery device for dispensing a fluid product, theautomatic drug delivery device comprising: a longitudinal housingextending along a longitudinal axis and having a proximal end close to adispensing site, a distal end opposite to the proximal end and a hollowinterior; a removable cap mounted to the proximal end of the housing; asyringe assembly arranged in a mounting position inside the housing andhaving a hollow syringe body and an injection needle formed with thehollow syringe body including the fluid product; a drive mechanism whichcan be triggered by a trigger element in order to initiate dispensing ofthe fluid product; wherein the drive mechanism is operatively coupledwith a safety shield movable within the longitudinal housing, whereinthe safety shield is biased into a proximal position in which itprotrudes out of the proximal end of the longitudinal housing in orderto cover a needle tip of the injection needle, and wherein the safetyshield is movable into a distal position in which the injection needleis exposed for injection; wherein the removable cap is axially retainedon the proximal end of the longitudinal housing by engagement ofretaining elements between the cap and the longitudinal housing, theretaining elements being disengaged by rotation of the cap relative tothe longitudinal housing to allow axial movement of the cap relative tothe housing to remove said cap, the axial movement of the cap relativeto the housing being supported by the biasing force applied to thesafety shield.
 2. The device as claimed in claim 1, wherein the safetyshield engages the removable cap with a proximal contact surface formedon or close to the proximal end of the safety shield when the removalcap is mounted to the longitudinal housing.
 3. The device as claimed inclaim 1, in which the retaining elements that axially retain theremovable cap on the proximal end of the longitudinal housing compriseinner protrusions formed on the proximal end of the longitudinal housingand projections formed inside the end cap body, the projections insidethe cap body comprise a recess within which the inner protrusion iscircumferentially restrained by chamfered projections.
 4. The device asclaimed in claim 1, in which the removable cap includes an end cap bodyhaving at least one inner surface, which defines an axially openreceiving portion, and having an inner ring, which is connected to theend cap body, wherein the inner surface of the removable end cap and theinner ring form a space for receiving a proximal end of the longitudinalhousing.
 5. The device as claimed in claim 1, wherein the removable capincludes at least one cam path surface, wherein the cam path surface isadapted or inclined relative to the longitudinal axis for guiding theremovable cap in proximal direction along at least a portion of arotation of the removable cap relative to the longitudinal housing. 6.The device as claimed in claim 5, in which the removable cap includes anend cap body having at least one inner surface, which defines an axiallyopen receiving portion, and having an inner ring, which is connected tothe end cap body, wherein the inner surface of the removable end cap andthe inner ring form a space for receiving a proximal end of thelongitudinal housing and wherein the cam path surface is located at theouter circumferential surface of the inner ring.
 7. The device asclaimed in claim 1, in which at least one safety shield projection isadapted to engage with a projection or recess of the cap in order tolimit movement of the safety shield in in distal direction within theremovable cap.
 8. The device as claimed claim 1, wherein the removablecap when mounted in its retained position to the longitudinal housing issecured to the longitudinal housing by a rupturable seal.
 9. The deviceas claimed claim 1, wherein the syringe assembly is provided with arigid needle shield fixed to a proximal end of the hollow syringe bodyand covering the needle together with its sharpened needle tip, whereinthe removable cap includes a flexible gripping element for engagingand/or restraining the rigid needle shield on its outer circumferentialsurface.
 10. A method of removing a removable cap from an automatic drugdelivery device according to any one of claims 1 to 9, in which themethod comprises: rotating the removable cap relative to thelongitudinal body to disengage the retaining elements between the capand the longitudinal housing; providing a removal force to separate theremovable cap from the longitudinal body; using the biasing forceapplied to the safety shield to assist with the separation of theremovable cap from the longitudinal body.
 11. The method as claimed inclaim 10, in which rotating the removable cap beyond the position inwhich the retaining elements between the cap and the longitudinalhousing are disengaged causes a cam path of the removable cap to engagewith a portion of the longitudinal housing and provide at least some ofthe removal force to separate the removable cap from the longitudinalbody.